Merge pull request #50 from crupest/refactor

Refactor : A Huge Step

85 files changed, 5870 insertions, 1418 deletions

diff --git a/Timeline/Authenticate/PrincipalExtensions.cs b/Timeline/Authenticate/PrincipalExtensions.cs
deleted file mode 100644
index fa39ea89..00000000
--- a/Timeline/Authenticate/PrincipalExtensions.cs
+++ /dev/null
@@ -1,13 +0,0 @@
-using System.Security.Principal;

-using Timeline.Entities;

-

-namespace Timeline.Authenticate

-{

-    public static class PrincipalExtensions

-    {

-        public static bool IsAdmin(this IPrincipal principal)

-        {

-            return principal.IsInRole(UserRoles.Admin);

-        }

-    }

-}

diff --git a/Timeline/Authenticate/Attribute.cs b/Timeline/Authentication/Attribute.cs
index 239a2a1c..370b37e1 100644
--- a/Timeline/Authenticate/Attribute.cs
+++ b/Timeline/Authentication/Attribute.cs
@@ -1,7 +1,7 @@
 using Microsoft.AspNetCore.Authorization;

 using Timeline.Entities;

 

-namespace Timeline.Authenticate

+namespace Timeline.Authentication

 {

     public class AdminAuthorizeAttribute : AuthorizeAttribute

     {

diff --git a/Timeline/Authenticate/AuthHandler.cs b/Timeline/Authentication/AuthHandler.cs
index f9409c1a..47ed1d71 100644
--- a/Timeline/Authenticate/AuthHandler.cs
+++ b/Timeline/Authentication/AuthHandler.cs
@@ -10,7 +10,7 @@ using System.Threading.Tasks;
 using Timeline.Models;

 using Timeline.Services;

 

-namespace Timeline.Authenticate

+namespace Timeline.Authentication

 {

     static class AuthConstants

     {

@@ -18,7 +18,7 @@ namespace Timeline.Authenticate
         public const string DisplayName = "My Jwt Auth Scheme";

     }

 

-    class AuthOptions : AuthenticationSchemeOptions

+    public class AuthOptions : AuthenticationSchemeOptions

     {

         /// <summary>

         /// The query param key to search for token. If null then query params are not searched for token. Default to <c>"token"</c>.

@@ -26,7 +26,7 @@ namespace Timeline.Authenticate
         public string TokenQueryParamKey { get; set; } = "token";

     }

 

-    class AuthHandler : AuthenticationHandler<AuthOptions>

+    public class AuthHandler : AuthenticationHandler<AuthOptions>

     {

         private readonly ILogger<AuthHandler> _logger;

         private readonly IUserService _userService;

@@ -39,14 +39,14 @@ namespace Timeline.Authenticate
         }

 

         // return null if no token is found

-        private string ExtractToken()

+        private string? ExtractToken()

         {

             // check the authorization header

             string header = Request.Headers[HeaderNames.Authorization];

-            if (!string.IsNullOrEmpty(header) && header.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))

+            if (!string.IsNullOrEmpty(header) && header.StartsWith("Bearer ", StringComparison.InvariantCultureIgnoreCase))

             {

                 var token = header.Substring("Bearer ".Length).Trim();

-                _logger.LogInformation("Token is found in authorization header. Token is {} .", token);

+                _logger.LogInformation(Resources.Authentication.AuthHandler.LogTokenFoundInHeader, token);

                 return token;

             }

 

@@ -57,7 +57,7 @@ namespace Timeline.Authenticate
                 string token = Request.Query[paramQueryKey];

                 if (!string.IsNullOrEmpty(token))

                 {

-                    _logger.LogInformation("Token is found in query param with key \"{}\". Token is {} .", paramQueryKey, token);

+                    _logger.LogInformation(Resources.Authentication.AuthHandler.LogTokenFoundInQuery, paramQueryKey, token);

                     return token;

                 }

             }

@@ -71,7 +71,7 @@ namespace Timeline.Authenticate
             var token = ExtractToken();

             if (string.IsNullOrEmpty(token))

             {

-                _logger.LogInformation("No jwt token is found.");

+                _logger.LogInformation(Resources.Authentication.AuthHandler.LogTokenNotFound);

                 return AuthenticateResult.NoResult();

             }

 

@@ -81,20 +81,16 @@ namespace Timeline.Authenticate
 

                 var identity = new ClaimsIdentity(AuthConstants.Scheme);

                 identity.AddClaim(new Claim(identity.NameClaimType, userInfo.Username, ClaimValueTypes.String));

-                identity.AddClaims(UserUtility.IsAdminToRoleArray(userInfo.Administrator).Select(role => new Claim(identity.RoleClaimType, role, ClaimValueTypes.String)));

+                identity.AddClaims(UserRoleConvert.ToArray(userInfo.Administrator).Select(role => new Claim(identity.RoleClaimType, role, ClaimValueTypes.String)));

 

                 var principal = new ClaimsPrincipal();

                 principal.AddIdentity(identity);

 

                 return AuthenticateResult.Success(new AuthenticationTicket(principal, AuthConstants.Scheme));

             }

-            catch (ArgumentException)

+            catch (Exception e) when (e! is ArgumentException)

             {

-                throw; // this exception usually means server error.

-            }

-            catch (Exception e)

-            {

-                _logger.LogInformation(e, "A jwt token validation failed.");

+                _logger.LogInformation(e, Resources.Authentication.AuthHandler.LogTokenValidationFail);

                 return AuthenticateResult.Fail(e);

             }

         }

diff --git a/Timeline/Authentication/PrincipalExtensions.cs b/Timeline/Authentication/PrincipalExtensions.cs
new file mode 100644
index 00000000..8d77ab62
--- /dev/null
+++ b/Timeline/Authentication/PrincipalExtensions.cs
@@ -0,0 +1,13 @@
+using System.Security.Principal;

+using Timeline.Entities;

+

+namespace Timeline.Authentication

+{

+    internal static class PrincipalExtensions

+    {

+        internal static bool IsAdministrator(this IPrincipal principal)

+        {

+            return principal.IsInRole(UserRoles.Admin);

+        }

+    }

+}

diff --git a/Timeline/Configs/DatabaseConfig.cs b/Timeline/Configs/DatabaseConfig.cs
index e24ecdfb..c9309b08 100644
--- a/Timeline/Configs/DatabaseConfig.cs
+++ b/Timeline/Configs/DatabaseConfig.cs
@@ -2,6 +2,6 @@ namespace Timeline.Configs
 {

     public class DatabaseConfig

     {

-        public string ConnectionString { get; set; }

+        public string ConnectionString { get; set; } = default!;

     }

 }

diff --git a/Timeline/Configs/JwtConfig.cs b/Timeline/Configs/JwtConfig.cs
index 8c61d7bc..8a17825e 100644
--- a/Timeline/Configs/JwtConfig.cs
+++ b/Timeline/Configs/JwtConfig.cs
@@ -2,9 +2,9 @@ namespace Timeline.Configs
 {

     public class JwtConfig

     {

-        public string Issuer { get; set; }

-        public string Audience { get; set; }

-        public string SigningKey { get; set; }

+        public string Issuer { get; set; } = default!;

+        public string Audience { get; set; } = default!;

+        public string SigningKey { get; set; } = default!;

 

         /// <summary>

         /// Set the default value of expire offset of jwt token.

diff --git a/Timeline/Controllers/UserTestController.cs b/Timeline/Controllers/Testing/TestingAuthController.cs
index 2a5f36a1..67b5b2ef 100644
--- a/Timeline/Controllers/UserTestController.cs
+++ b/Timeline/Controllers/Testing/TestingAuthController.cs
@@ -1,12 +1,12 @@
 using Microsoft.AspNetCore.Authorization;

 using Microsoft.AspNetCore.Mvc;

-using Timeline.Authenticate;

+using Timeline.Authentication;

 

-namespace Timeline.Controllers

+namespace Timeline.Controllers.Testing

 {

-    [Route("Test/User")]

+    [Route("testing/auth")]

     [ApiController]

-    public class UserTestController : Controller

+    public class TestingAuthController : Controller

     {

         [HttpGet("[action]")]

         [Authorize]

diff --git a/Timeline/Controllers/TokenController.cs b/Timeline/Controllers/TokenController.cs
index 3c166448..4e32d26f 100644
--- a/Timeline/Controllers/TokenController.cs
+++ b/Timeline/Controllers/TokenController.cs
@@ -3,71 +3,84 @@ using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Logging;

 using Microsoft.IdentityModel.Tokens;

 using System;

-using System.Collections.Generic;

 using System.Threading.Tasks;

 using Timeline.Models.Http;

 using Timeline.Services;

-using static Timeline.Helpers.MyLogHelper;

+using Timeline.Helpers;

+using Microsoft.Extensions.Localization;

+using System.Globalization;

+using static Timeline.Resources.Controllers.TokenController;

 

-namespace Timeline.Controllers

+namespace Timeline

 {

-    [Route("token")]

-    [ApiController]

-    public class TokenController : Controller

+    public static partial class ErrorCodes

     {

-        private static class LoggingEventIds

-        {

-            public const int CreateSucceeded = 1000;

-            public const int CreateFailed = 1001;

-

-            public const int VerifySucceeded = 2000;

-            public const int VerifyFailed = 2001;

-        }

-

-        public static class ErrorCodes

+        public static partial class Http

         {

-            public const int Create_UserNotExist = -1001;

-            public const int Create_BadPassword = -1002;

-            public const int Create_BadExpireOffset = -1003;

+            public static class Token // bbb = 001

+            {

+                public static class Create // cc = 01

+                {

+                    public const int BadCredential = 10010101;

+                }

 

-            public const int Verify_BadToken = -2001;

-            public const int Verify_UserNotExist = -2002;

-            public const int Verify_BadVersion = -2003;

-            public const int Verify_Expired = -2004;

+                public static class Verify // cc = 02

+                {

+                    public const int BadFormat = 10010201;

+                    public const int UserNotExist = 10010202;

+                    public const int OldVersion = 10010203;

+                    public const int Expired = 10010204;

+                }

+            }

         }

+    }

+}

 

+namespace Timeline.Controllers

+{

+    [Route("token")]

+    [ApiController]

+    public class TokenController : Controller

+    {

         private readonly IUserService _userService;

         private readonly ILogger<TokenController> _logger;

         private readonly IClock _clock;

+        private readonly IStringLocalizer<TokenController> _localizer;

 

-        public TokenController(IUserService userService, ILogger<TokenController> logger, IClock clock)

+        public TokenController(IUserService userService, ILogger<TokenController> logger, IClock clock, IStringLocalizer<TokenController> localizer)

         {

             _userService = userService;

             _logger = logger;

             _clock = clock;

+            _localizer = localizer;

         }

 

         [HttpPost("create")]

         [AllowAnonymous]

-        public async Task<IActionResult> Create([FromBody] CreateTokenRequest request)

+        public async Task<ActionResult<CreateTokenResponse>> Create([FromBody] CreateTokenRequest request)

         {

-            void LogFailure(string reason, int code, Exception e = null)

+            void LogFailure(string reason, Exception? e = null)

             {

-                _logger.LogInformation(LoggingEventIds.CreateFailed, e, FormatLogMessage("Attemp to login failed.",

-                    Pair("Reason", reason),

-                    Pair("Code", code),

-                    Pair("Username", request.Username),

-                    Pair("Password", request.Password),

-                    Pair("Expire Offset (in days)", request.ExpireOffset)));

+                _logger.LogInformation(e, Log.Format(LogCreateFailure,

+                    ("Reason", reason),

+                    ("Username", request.Username),

+                    ("Password", request.Password),

+                    ("Expire (in days)", request.Expire)

+                ));

             }

 

             try

             {

-                var expiredTime = request.ExpireOffset == null ? null : (DateTime?)(_clock.GetCurrentTime().AddDays(request.ExpireOffset.Value));

-                var result = await _userService.CreateToken(request.Username, request.Password, expiredTime);

-                _logger.LogInformation(LoggingEventIds.CreateSucceeded, FormatLogMessage("Attemp to login succeeded.",

-                    Pair("Username", request.Username),

-                    Pair("Expire Time", expiredTime == null ? "default" : expiredTime.Value.ToString())));

+                DateTime? expireTime = null;

+                if (request.Expire != null)

+                    expireTime = _clock.GetCurrentTime().AddDays(request.Expire.Value);

+

+                var result = await _userService.CreateToken(request.Username, request.Password, expireTime);

+

+                _logger.LogInformation(Log.Format(LogCreateSuccess,

+                    ("Username", request.Username),

+                    ("Expire At", expireTime?.ToString(CultureInfo.CurrentUICulture.DateTimeFormat) ?? "default")

+                ));

                 return Ok(new CreateTokenResponse

                 {

                     Token = result.Token,

@@ -76,75 +89,71 @@ namespace Timeline.Controllers
             }

             catch (UserNotExistException e)

             {

-                var code = ErrorCodes.Create_UserNotExist;

-                LogFailure("User does not exist.", code, e);

-                return BadRequest(new CommonResponse(code, "Bad username or password."));

+                LogFailure(LogUserNotExist, e);

+                return BadRequest(new CommonResponse(ErrorCodes.Http.Token.Create.BadCredential,

+                    _localizer["ErrorBadCredential"]));

             }

             catch (BadPasswordException e)

             {

-                var code = ErrorCodes.Create_BadPassword;

-                LogFailure("Password is wrong.", code, e);

-                return BadRequest(new CommonResponse(code, "Bad username or password."));

+                LogFailure(LogBadPassword, e);

+                return BadRequest(new CommonResponse(ErrorCodes.Http.Token.Create.BadCredential,

+                     _localizer["ErrorBadCredential"]));

             }

         }

 

         [HttpPost("verify")]

         [AllowAnonymous]

-        public async Task<IActionResult> Verify([FromBody] VerifyTokenRequest request)

+        public async Task<ActionResult<VerifyTokenResponse>> Verify([FromBody] VerifyTokenRequest request)

         {

-            void LogFailure(string reason, int code, Exception e = null, params KeyValuePair<string, object>[] otherProperties)

+            void LogFailure(string reason, Exception? e = null, params (string, object?)[] otherProperties)

             {

-                var properties = new KeyValuePair<string, object>[3 + otherProperties.Length];

-                properties[0] = Pair("Reason", reason);

-                properties[1] = Pair("Code", code);

-                properties[2] = Pair("Token", request.Token);

-                otherProperties.CopyTo(properties, 3);

-                _logger.LogInformation(LoggingEventIds.VerifyFailed, e, FormatLogMessage("Token verification failed.", properties));

+                var properties = new (string, object?)[2 + otherProperties.Length];

+                properties[0] = ("Reason", reason);

+                properties[1] = ("Token", request.Token);

+                otherProperties.CopyTo(properties, 2);

+                _logger.LogInformation(e, Log.Format(LogVerifyFailure, properties));

             }

 

             try

             {

                 var result = await _userService.VerifyToken(request.Token);

-                _logger.LogInformation(LoggingEventIds.VerifySucceeded,

-                    FormatLogMessage("Token verification succeeded.",

-                    Pair("Username", result.Username), Pair("Token", request.Token)));

+                _logger.LogInformation(Log.Format(LogVerifySuccess,

+                    ("Username", result.Username), ("Token", request.Token)));

                 return Ok(new VerifyTokenResponse

                 {

                     User = result

                 });

             }

-            catch (JwtTokenVerifyException e)

+            catch (JwtVerifyException e)

             {

-                if (e.ErrorCode == JwtTokenVerifyException.ErrorCodes.Expired)

+                if (e.ErrorCode == JwtVerifyException.ErrorCodes.Expired)

                 {

-                    const string message = "Token is expired.";

-                    var code = ErrorCodes.Verify_Expired;

                     var innerException = e.InnerException as SecurityTokenExpiredException;

-                    LogFailure(message, code, e, Pair("Expires", innerException.Expires));

-                    return BadRequest(new CommonResponse(code, message));

+                    LogFailure(LogVerifyExpire, e, ("Expires", innerException?.Expires),

+                        ("Current Time", _clock.GetCurrentTime()));

+                    return BadRequest(new CommonResponse(

+                        ErrorCodes.Http.Token.Verify.Expired, _localizer["ErrorVerifyExpire"]));

+                }

+                else if (e.ErrorCode == JwtVerifyException.ErrorCodes.OldVersion)

+                {

+                    var innerException = e.InnerException as JwtBadVersionException;

+                    LogFailure(LogVerifyOldVersion, e,

+                        ("Token Version", innerException?.TokenVersion), ("Required Version", innerException?.RequiredVersion));

+                    return BadRequest(new CommonResponse(

+                        ErrorCodes.Http.Token.Verify.OldVersion, _localizer["ErrorVerifyOldVersion"]));

                 }

                 else

                 {

-                    const string message = "Token is of bad format.";

-                    var code = ErrorCodes.Verify_BadToken;

-                    LogFailure(message, code, e);

-                    return BadRequest(new CommonResponse(code, message));

+                    LogFailure(LogVerifyBadFormat, e);

+                    return BadRequest(new CommonResponse(

+                        ErrorCodes.Http.Token.Verify.BadFormat, _localizer["ErrorVerifyBadFormat"]));

                 }

             }

             catch (UserNotExistException e)

             {

-                const string message = "User does not exist. Administrator might have deleted this user.";

-                var code = ErrorCodes.Verify_UserNotExist;

-                LogFailure(message, code, e);

-                return BadRequest(new CommonResponse(code, message));

-            }

-            catch (BadTokenVersionException e)

-            {

-                const string message = "Token has a old version.";

-                var code = ErrorCodes.Verify_BadVersion;

-                LogFailure(message, code, e);

-                _logger.LogInformation(LoggingEventIds.VerifyFailed, e, "Attemp to verify a bad token because version is old. Code: {} Token: {}.", code, request.Token);

-                return BadRequest(new CommonResponse(code, message));

+                LogFailure(LogVerifyUserNotExist, e);

+                return BadRequest(new CommonResponse(

+                    ErrorCodes.Http.Token.Verify.UserNotExist, _localizer["ErrorVerifyUserNotExist"]));

             }

         }

     }

diff --git a/Timeline/Controllers/UserAvatarController.cs b/Timeline/Controllers/UserAvatarController.cs
index e77076ca..838a3928 100644
--- a/Timeline/Controllers/UserAvatarController.cs
+++ b/Timeline/Controllers/UserAvatarController.cs
@@ -1,68 +1,75 @@
 using Microsoft.AspNetCore.Authorization;

 using Microsoft.AspNetCore.Http;

 using Microsoft.AspNetCore.Mvc;

+using Microsoft.Extensions.Localization;

 using Microsoft.Extensions.Logging;

 using Microsoft.Net.Http.Headers;

 using System;

 using System.Linq;

 using System.Threading.Tasks;

-using Timeline.Authenticate;

+using Timeline.Authentication;

 using Timeline.Filters;

+using Timeline.Helpers;

 using Timeline.Models.Http;

+using Timeline.Models.Validation;

 using Timeline.Services;

 

-namespace Timeline.Controllers

+namespace Timeline

 {

-    [ApiController]

-    public class UserAvatarController : Controller

+    public static partial class ErrorCodes

     {

-        public static class ErrorCodes

+        public static partial class Http

         {

-            public const int Get_UserNotExist = -1001;

-

-            public const int Put_UserNotExist = -2001;

-            public const int Put_Forbid = -2002;

-            public const int Put_BadFormat_CantDecode = -2011;

-            public const int Put_BadFormat_UnmatchedFormat = -2012;

-            public const int Put_BadFormat_BadSize = -2013;

-            public const int Put_Content_TooBig = -2021;

-            public const int Put_Content_UnmatchedLength_Less = -2022;

-            public const int Put_Content_UnmatchedLength_Bigger = -2023;

+            public static class UserAvatar // bbb = 003

+            {

+                public static class Get // cc = 01

+                {

+                    public const int UserNotExist = 10030101;

+                }

 

-            public const int Delete_UserNotExist = -3001;

-            public const int Delete_Forbid = -3002;

+                public static class Put // cc = 02

+                {

+                    public const int UserNotExist = 10030201;

+                    public const int Forbid = 10030202;

+                    public const int BadFormat_CantDecode = 10030203;

+                    public const int BadFormat_UnmatchedFormat = 10030204;

+                    public const int BadFormat_BadSize = 10030205;

 

+                }

 

-            public static int From(AvatarDataException.ErrorReason error)

-            {

-                switch (error)

+                public static class Delete // cc = 03

                 {

-                    case AvatarDataException.ErrorReason.CantDecode:

-                        return Put_BadFormat_CantDecode;

-                    case AvatarDataException.ErrorReason.UnmatchedFormat:

-                        return Put_BadFormat_UnmatchedFormat;

-                    case AvatarDataException.ErrorReason.BadSize:

-                        return Put_BadFormat_BadSize;

-                    default:

-                        throw new Exception("Unknown AvatarDataException.ErrorReason value.");

+                    public const int UserNotExist = 10030301;

+                    public const int Forbid = 10030302;

                 }

             }

         }

+    }

+}

 

+namespace Timeline.Controllers

+{

+    [ApiController]

+    public class UserAvatarController : Controller

+    {

         private readonly ILogger<UserAvatarController> _logger;

 

         private readonly IUserAvatarService _service;

 

-        public UserAvatarController(ILogger<UserAvatarController> logger, IUserAvatarService service)

+        private readonly IStringLocalizerFactory _localizerFactory;

+        private readonly IStringLocalizer<UserAvatarController> _localizer;

+

+        public UserAvatarController(ILogger<UserAvatarController> logger, IUserAvatarService service, IStringLocalizerFactory localizerFactory)

         {

             _logger = logger;

             _service = service;

+            _localizerFactory = localizerFactory;

+            _localizer = new StringLocalizer<UserAvatarController>(localizerFactory);

         }

 

         [HttpGet("users/{username}/avatar")]

-        [Authorize]

         [ResponseCache(NoStore = false, Location = ResponseCacheLocation.None, Duration = 0)]

-        public async Task<IActionResult> Get([FromRoute] string username)

+        public async Task<IActionResult> Get([FromRoute][Username] string username)

         {

             const string IfNonMatchHeaderKey = "If-None-Match";

 

@@ -74,11 +81,16 @@ namespace Timeline.Controllers
                 if (Request.Headers.TryGetValue(IfNonMatchHeaderKey, out var value))

                 {

                     if (!EntityTagHeaderValue.TryParseStrictList(value, out var eTagList))

-                        return BadRequest(CommonResponse.BadIfNonMatch());

+                    {

+                        _logger.LogInformation(Log.Format(Resources.Controllers.UserAvatarController.LogGetBadIfNoneMatch,

+                            ("Username", username), ("If-None-Match", value)));

+                        return BadRequest(HeaderErrorResponse.BadIfNonMatch(_localizerFactory));

+                    }

 

                     if (eTagList.FirstOrDefault(e => e.Equals(eTag)) != null)

                     {

                         Response.Headers.Add("ETag", eTagValue);

+                        _logger.LogInformation(Log.Format(Resources.Controllers.UserAvatarController.LogGetReturnNotModify, ("Username", username)));

                         return StatusCode(StatusCodes.Status304NotModified);

                     }

                 }

@@ -86,12 +98,13 @@ namespace Timeline.Controllers
                 var avatarInfo = await _service.GetAvatar(username);

                 var avatar = avatarInfo.Avatar;

 

+                _logger.LogInformation(Log.Format(Resources.Controllers.UserAvatarController.LogGetReturnData, ("Username", username)));

                 return File(avatar.Data, avatar.Type, new DateTimeOffset(avatarInfo.LastModified), eTag);

             }

             catch (UserNotExistException e)

             {

-                _logger.LogInformation(e, $"Attempt to get a avatar of a non-existent user failed. Username: {username} .");

-                return NotFound(new CommonResponse(ErrorCodes.Get_UserNotExist, "User does not exist."));

+                _logger.LogInformation(e, Log.Format(Resources.Controllers.UserAvatarController.LogGetUserNotExist, ("Username", username)));

+                return NotFound(new CommonResponse(ErrorCodes.Http.UserAvatar.Get.UserNotExist, _localizer["ErrorGetUserNotExist"]));

             }

         }

 

@@ -99,18 +112,18 @@ namespace Timeline.Controllers
         [Authorize]

         [RequireContentType, RequireContentLength]

         [Consumes("image/png", "image/jpeg", "image/gif", "image/webp")]

-        public async Task<IActionResult> Put(string username)

+        public async Task<IActionResult> Put([FromRoute][Username] string username)

         {

-            var contentLength = Request.ContentLength.Value;

+            var contentLength = Request.ContentLength!.Value;

             if (contentLength > 1000 * 1000 * 10)

-                return BadRequest(new CommonResponse(ErrorCodes.Put_Content_TooBig,

-                    "Content can't be bigger than 10MB."));

+                return BadRequest(ContentErrorResponse.TooBig(_localizerFactory, "10MB"));

 

-            if (!User.IsAdmin() && User.Identity.Name != username)

+            if (!User.IsAdministrator() && User.Identity.Name != username)

             {

-                _logger.LogInformation($"Attempt to put a avatar of other user as a non-admin failed. Operator Username: {User.Identity.Name} ;  Username To Put Avatar: {username} .");

+                _logger.LogInformation(Log.Format(Resources.Controllers.UserAvatarController.LogPutForbid,

+                    ("Operator Username", User.Identity.Name), ("Username To Put Avatar", username)));

                 return StatusCode(StatusCodes.Status403Forbidden,

-                    new CommonResponse(ErrorCodes.Put_Forbid, "Normal user can't change other's avatar."));

+                    new CommonResponse(ErrorCodes.Http.UserAvatar.Put.Forbid, _localizer["ErrorPutForbid"]));

             }

 

             try

@@ -119,13 +132,11 @@ namespace Timeline.Controllers
                 var bytesRead = await Request.Body.ReadAsync(data);

 

                 if (bytesRead != contentLength)

-                    return BadRequest(new CommonResponse(ErrorCodes.Put_Content_UnmatchedLength_Less,

-                        $"Content length in header is {contentLength} but actual length is {bytesRead}."));

+                    return BadRequest(ContentErrorResponse.UnmatchedLength_Smaller(_localizerFactory));

 

                 var extraByte = new byte[1];

                 if (await Request.Body.ReadAsync(extraByte) != 0)

-                    return BadRequest(new CommonResponse(ErrorCodes.Put_Content_UnmatchedLength_Bigger,

-                        $"Content length in header is {contentLength} but actual length is bigger than that."));

+                    return BadRequest(ContentErrorResponse.UnmatchedLength_Bigger(_localizerFactory));

 

                 await _service.SetAvatar(username, new Avatar

                 {

@@ -133,43 +144,57 @@ namespace Timeline.Controllers
                     Type = Request.ContentType

                 });

 

-                _logger.LogInformation($"Succeed to put a avatar of a user. Username: {username} ; Mime Type: {Request.ContentType} .");

+                _logger.LogInformation(Log.Format(Resources.Controllers.UserAvatarController.LogPutSuccess,

+                    ("Username", username), ("Mime Type", Request.ContentType)));

                 return Ok();

             }

             catch (UserNotExistException e)

             {

-                _logger.LogInformation(e, $"Attempt to put a avatar of a non-existent user failed. Username: {username} .");

-                return BadRequest(new CommonResponse(ErrorCodes.Put_UserNotExist, "User does not exist."));

+                _logger.LogInformation(e, Log.Format(Resources.Controllers.UserAvatarController.LogPutUserNotExist, ("Username", username)));

+                return BadRequest(new CommonResponse(ErrorCodes.Http.UserAvatar.Put.UserNotExist, _localizer["ErrorPutUserNotExist"]));

             }

-            catch (AvatarDataException e)

+            catch (AvatarFormatException e)

             {

-                _logger.LogInformation(e, $"Attempt to put a avatar of a bad format failed. Username: {username} .");

-                return BadRequest(new CommonResponse(ErrorCodes.From(e.Error), "Bad format."));

+                var (code, message) = e.Error switch

+                {

+                    AvatarFormatException.ErrorReason.CantDecode =>

+                        (ErrorCodes.Http.UserAvatar.Put.BadFormat_CantDecode, _localizer["ErrorPutBadFormatCantDecode"]),

+                    AvatarFormatException.ErrorReason.UnmatchedFormat =>

+                       (ErrorCodes.Http.UserAvatar.Put.BadFormat_UnmatchedFormat, _localizer["ErrorPutBadFormatUnmatchedFormat"]),

+                    AvatarFormatException.ErrorReason.BadSize =>

+                       (ErrorCodes.Http.UserAvatar.Put.BadFormat_BadSize, _localizer["ErrorPutBadFormatBadSize"]),

+                    _ =>

+                        throw new Exception(Resources.Controllers.UserAvatarController.ExceptionUnknownAvatarFormatError)

+                };

+

+                _logger.LogInformation(e, Log.Format(Resources.Controllers.UserAvatarController.LogPutUserBadFormat, ("Username", username)));

+                return BadRequest(new CommonResponse(code, message));

             }

         }

 

         [HttpDelete("users/{username}/avatar")]

         [Authorize]

-        public async Task<IActionResult> Delete([FromRoute] string username)

+        public async Task<IActionResult> Delete([FromRoute][Username] string username)

         {

-            if (!User.IsAdmin() && User.Identity.Name != username)

+            if (!User.IsAdministrator() && User.Identity.Name != username)

             {

-                _logger.LogInformation($"Attempt to delete a avatar of other user as a non-admin failed. Operator Username: {User.Identity.Name} ;  Username To Put Avatar: {username} .");

+                _logger.LogInformation(Log.Format(Resources.Controllers.UserAvatarController.LogPutUserBadFormat,

+                    ("Operator Username", User.Identity.Name), ("Username To Delete Avatar", username)));

                 return StatusCode(StatusCodes.Status403Forbidden,

-                    new CommonResponse(ErrorCodes.Delete_Forbid, "Normal user can't delete other's avatar."));

+                    new CommonResponse(ErrorCodes.Http.UserAvatar.Delete.Forbid, _localizer["ErrorDeleteForbid"]));

             }

 

             try

             {

                 await _service.SetAvatar(username, null);

 

-                _logger.LogInformation($"Succeed to delete a avatar of a user. Username: {username} .");

+                _logger.LogInformation(Log.Format(Resources.Controllers.UserAvatarController.LogDeleteSuccess, ("Username", username)));

                 return Ok();

             }

             catch (UserNotExistException e)

             {

-                _logger.LogInformation(e, $"Attempt to delete a avatar of a non-existent user failed. Username: {username} .");

-                return BadRequest(new CommonResponse(ErrorCodes.Delete_UserNotExist, "User does not exist."));

+                _logger.LogInformation(e, Log.Format(Resources.Controllers.UserAvatarController.LogDeleteNotExist, ("Username", username)));

+                return BadRequest(new CommonResponse(ErrorCodes.Http.UserAvatar.Delete.UserNotExist, _localizer["ErrorDeleteUserNotExist"]));

             }

         }

     }

diff --git a/Timeline/Controllers/UserController.cs b/Timeline/Controllers/UserController.cs
index bd13f0a3..1771dc85 100644
--- a/Timeline/Controllers/UserController.cs
+++ b/Timeline/Controllers/UserController.cs
@@ -1,40 +1,70 @@
 using Microsoft.AspNetCore.Authorization;

 using Microsoft.AspNetCore.Mvc;

+using Microsoft.Extensions.Localization;

 using Microsoft.Extensions.Logging;

-using System;

 using System.Threading.Tasks;

-using Timeline.Authenticate;

+using Timeline.Authentication;

+using Timeline.Helpers;

 using Timeline.Models;

 using Timeline.Models.Http;

+using Timeline.Models.Validation;

 using Timeline.Services;

-using static Timeline.Helpers.MyLogHelper;

+using static Timeline.Resources.Controllers.UserController;

 

-namespace Timeline.Controllers

+namespace Timeline

 {

-    [ApiController]

-    public class UserController : Controller

+    public static partial class ErrorCodes

     {

-        public static class ErrorCodes

+        public static partial class Http

         {

-            public const int Get_NotExist = -1001;

+            public static class User // bbb = 002

+            {

+                public static class Get // cc = 01

+                {

+                    public const int NotExist = 10020101; // dd = 01

+                }

 

-            public const int Put_BadUsername = -2001;

+                public static class Patch // cc = 03

+                {

+                    public const int NotExist = 10020301; // dd = 01

+                }

 

-            public const int Patch_NotExist = -3001;

+                public static class Op // cc = 1x

+                {

+                    public static class ChangeUsername // cc = 11

+                    {

+                        public const int NotExist = 10021101; // dd = 01

+                        public const int AlreadyExist = 10021102; // dd = 02

+                    }

 

-            public const int ChangeUsername_NotExist = -4001;

-            public const int ChangeUsername_AlreadyExist = -4002;

+                    public static class ChangePassword // cc = 12

+                    {

+                        public const int BadOldPassword = 10021201; // dd = 01

+                    }

+                }

 

-            public const int ChangePassword_BadOldPassword = -5001;

+            }

         }

+    }

+}

+

+namespace Timeline.Controllers

+{

+    [ApiController]

+    public class UserController : Controller

+    {

 

         private readonly ILogger<UserController> _logger;

         private readonly IUserService _userService;

+        private readonly IStringLocalizerFactory _localizerFactory;

+        private readonly IStringLocalizer _localizer;

 

-        public UserController(ILogger<UserController> logger, IUserService userService)

+        public UserController(ILogger<UserController> logger, IUserService userService, IStringLocalizerFactory localizerFactory)

         {

             _logger = logger;

             _userService = userService;

+            _localizerFactory = localizerFactory;

+            _localizer = localizerFactory.Create(GetType());

         }

 

         [HttpGet("users"), AdminAuthorize]

@@ -44,44 +74,36 @@ namespace Timeline.Controllers
         }

 

         [HttpGet("users/{username}"), AdminAuthorize]

-        public async Task<IActionResult> Get([FromRoute] string username)

+        public async Task<ActionResult<UserInfo>> Get([FromRoute][Username] string username)

         {

             var user = await _userService.GetUser(username);

             if (user == null)

             {

-                _logger.LogInformation(FormatLogMessage("Attempt to get a non-existent user.", Pair("Username", username)));

-                return NotFound(new CommonResponse(ErrorCodes.Get_NotExist, "The user does not exist."));

+                _logger.LogInformation(Log.Format(LogGetUserNotExist, ("Username", username)));

+                return NotFound(new CommonResponse(ErrorCodes.Http.User.Get.NotExist, _localizer["ErrorGetUserNotExist"]));

             }

             return Ok(user);

         }

 

         [HttpPut("users/{username}"), AdminAuthorize]

-        public async Task<IActionResult> Put([FromBody] UserPutRequest request, [FromRoute] string username)

+        public async Task<ActionResult<CommonPutResponse>> Put([FromBody] UserPutRequest request, [FromRoute][Username] string username)

         {

-            try

-            {

-                var result = await _userService.PutUser(username, request.Password, request.Administrator.Value);

-                switch (result)

-                {

-                    case PutResult.Created:

-                        _logger.LogInformation(FormatLogMessage("A user is created.", Pair("Username", username)));

-                        return CreatedAtAction("Get", new { username }, CommonPutResponse.Created);

-                    case PutResult.Modified:

-                        _logger.LogInformation(FormatLogMessage("A user is modified.", Pair("Username", username)));

-                        return Ok(CommonPutResponse.Modified);

-                    default:

-                        throw new Exception("Unreachable code.");

-                }

-            }

-            catch (UsernameBadFormatException e)

+            var result = await _userService.PutUser(username, request.Password, request.Administrator!.Value);

+            switch (result)

             {

-                _logger.LogInformation(e, FormatLogMessage("Attempt to create a user with bad username failed.", Pair("Username", username)));

-                return BadRequest(new CommonResponse(ErrorCodes.Put_BadUsername, "Username is of bad format."));

+                case PutResult.Create:

+                    _logger.LogInformation(Log.Format(LogPutCreate, ("Username", username)));

+                    return CreatedAtAction("Get", new { username }, CommonPutResponse.Create(_localizerFactory));

+                case PutResult.Modify:

+                    _logger.LogInformation(Log.Format(LogPutModify, ("Username", username)));

+                    return Ok(CommonPutResponse.Modify(_localizerFactory));

+                default:

+                    throw new InvalidBranchException();

             }

         }

 

         [HttpPatch("users/{username}"), AdminAuthorize]

-        public async Task<IActionResult> Patch([FromBody] UserPatchRequest request, [FromRoute] string username)

+        public async Task<ActionResult> Patch([FromBody] UserPatchRequest request, [FromRoute][Username] string username)

         {

             try

             {

@@ -90,66 +112,67 @@ namespace Timeline.Controllers
             }

             catch (UserNotExistException e)

             {

-                _logger.LogInformation(e, FormatLogMessage("Attempt to patch a non-existent user.", Pair("Username", username)));

-                return NotFound(new CommonResponse(ErrorCodes.Patch_NotExist, "The user does not exist."));

+                _logger.LogInformation(e, Log.Format(LogPatchUserNotExist, ("Username", username)));

+                return NotFound(new CommonResponse(ErrorCodes.Http.User.Patch.NotExist, _localizer["ErrorPatchUserNotExist"]));

             }

         }

 

         [HttpDelete("users/{username}"), AdminAuthorize]

-        public async Task<IActionResult> Delete([FromRoute] string username)

+        public async Task<ActionResult<CommonDeleteResponse>> Delete([FromRoute][Username] string username)

         {

             try

             {

                 await _userService.DeleteUser(username);

-                _logger.LogInformation(FormatLogMessage("A user is deleted.", Pair("Username", username)));

-                return Ok(CommonDeleteResponse.Deleted);

+                _logger.LogInformation(Log.Format(LogDeleteDelete, ("Username", username)));

+                return Ok(CommonDeleteResponse.Delete(_localizerFactory));

             }

             catch (UserNotExistException e)

             {

-                _logger.LogInformation(e, FormatLogMessage("Attempt to delete a non-existent user.", Pair("Username", username)));

-                return Ok(CommonDeleteResponse.NotExists);

+                _logger.LogInformation(e, Log.Format(LogDeleteNotExist, ("Username", username)));

+                return Ok(CommonDeleteResponse.NotExist(_localizerFactory));

             }

         }

 

         [HttpPost("userop/changeusername"), AdminAuthorize]

-        public async Task<IActionResult> ChangeUsername([FromBody] ChangeUsernameRequest request)

+        public async Task<ActionResult> ChangeUsername([FromBody] ChangeUsernameRequest request)

         {

             try

             {

                 await _userService.ChangeUsername(request.OldUsername, request.NewUsername);

-                _logger.LogInformation(FormatLogMessage("A user changed username.",

-                    Pair("Old Username", request.OldUsername), Pair("New Username", request.NewUsername)));

+                _logger.LogInformation(Log.Format(LogChangeUsernameSuccess,

+                    ("Old Username", request.OldUsername), ("New Username", request.NewUsername)));

                 return Ok();

             }

             catch (UserNotExistException e)

             {

-                _logger.LogInformation(e, FormatLogMessage("Attempt to change a non-existent user's username failed.",

-                    Pair("Old Username", request.OldUsername), Pair("New Username", request.NewUsername)));

-                return BadRequest(new CommonResponse(ErrorCodes.ChangeUsername_NotExist, $"The user {request.OldUsername} does not exist."));

+                _logger.LogInformation(e, Log.Format(LogChangeUsernameNotExist,

+                    ("Old Username", request.OldUsername), ("New Username", request.NewUsername)));

+                return BadRequest(new CommonResponse(ErrorCodes.Http.User.Op.ChangeUsername.NotExist, _localizer["ErrorChangeUsernameNotExist", request.OldUsername]));

             }

-            catch (UserAlreadyExistException e)

+            catch (UsernameConfictException e)

             {

-                _logger.LogInformation(e, FormatLogMessage("Attempt to change a user's username to a existent one failed.",

-                    Pair("Old Username", request.OldUsername), Pair("New Username", request.NewUsername)));

-                return BadRequest(new CommonResponse(ErrorCodes.ChangeUsername_AlreadyExist, $"The user {request.NewUsername} already exists."));

+                _logger.LogInformation(e, Log.Format(LogChangeUsernameAlreadyExist,

+                    ("Old Username", request.OldUsername), ("New Username", request.NewUsername)));

+                return BadRequest(new CommonResponse(ErrorCodes.Http.User.Op.ChangeUsername.AlreadyExist, _localizer["ErrorChangeUsernameAlreadyExist"]));

             }

             // there is no need to catch bad format exception because it is already checked in model validation.

         }

 

         [HttpPost("userop/changepassword"), Authorize]

-        public async Task<IActionResult> ChangePassword([FromBody] ChangePasswordRequest request)

+        public async Task<ActionResult> ChangePassword([FromBody] ChangePasswordRequest request)

         {

             try

             {

-                await _userService.ChangePassword(User.Identity.Name, request.OldPassword, request.NewPassword);

-                _logger.LogInformation(FormatLogMessage("A user changed password.", Pair("Username", User.Identity.Name)));

+                await _userService.ChangePassword(User.Identity.Name!, request.OldPassword, request.NewPassword);

+                _logger.LogInformation(Log.Format(LogChangePasswordSuccess, ("Username", User.Identity.Name)));

                 return Ok();

             }

             catch (BadPasswordException e)

             {

-                _logger.LogInformation(e, FormatLogMessage("A user attempt to change password but old password is wrong.",

-                    Pair("Username", User.Identity.Name), Pair("Old Password", request.OldPassword)));

-                return BadRequest(new CommonResponse(ErrorCodes.ChangePassword_BadOldPassword, "Old password is wrong."));

+                _logger.LogInformation(e, Log.Format(LogChangePasswordBadPassword,

+                    ("Username", User.Identity.Name), ("Old Password", request.OldPassword)));

+                return BadRequest(new CommonResponse(ErrorCodes.Http.User.Op.ChangePassword.BadOldPassword,

+                    _localizer["ErrorChangePasswordBadPassword"]));

             }

             // User can't be non-existent or the token is bad. 

         }

diff --git a/Timeline/Controllers/UserDetailController.cs b/Timeline/Controllers/UserDetailController.cs
deleted file mode 100644
index 5e1183c1..00000000
--- a/Timeline/Controllers/UserDetailController.cs
+++ /dev/null
@@ -1,96 +0,0 @@
-using Microsoft.AspNetCore.Authorization;

-using Microsoft.AspNetCore.Http;

-using Microsoft.AspNetCore.Mvc;

-using Microsoft.Extensions.Logging;

-using System.Threading.Tasks;

-using Timeline.Authenticate;

-using Timeline.Models;

-using Timeline.Models.Http;

-using Timeline.Services;

-

-namespace Timeline.Controllers

-{

-    [Route("users/{username}")]

-    [ProducesErrorResponseType(typeof(CommonResponse))]

-    [ApiController]

-    public class UserDetailController : Controller

-    {

-        public static class ErrorCodes

-        {

-            public const int Get_UserNotExist = -1001;

-

-            public const int Patch_Forbid = -2001;

-            public const int Patch_UserNotExist = -2002;

-

-            public const int GetNickname_UserNotExist = -3001;

-        }

-

-        private readonly ILogger<UserDetailController> _logger;

-        private readonly IUserDetailService _service;

-

-        public UserDetailController(ILogger<UserDetailController> logger, IUserDetailService service)

-        {

-            _logger = logger;

-            _service = service;

-        }

-

-        [HttpGet("nickname")]

-        [UserAuthorize]

-        [ProducesResponseType(StatusCodes.Status200OK, Type = typeof(UserDetail))]

-        [ProducesResponseType(StatusCodes.Status404NotFound)]

-        public async Task<IActionResult> GetNickname([FromRoute] string username)

-        {

-            try

-            {

-                var nickname = await _service.GetUserNickname(username);

-                return Ok(new UserDetail

-                {

-                    Nickname = nickname

-                });

-            }

-            catch (UserNotExistException)

-            {

-                return NotFound(new CommonResponse(ErrorCodes.GetNickname_UserNotExist, "The user does not exist."));

-            }

-        }

-

-        [HttpGet("details")]

-        [UserAuthorize]

-        [ProducesResponseType(StatusCodes.Status200OK, Type = typeof(UserDetail))]

-        [ProducesResponseType(StatusCodes.Status404NotFound)]

-        public async Task<IActionResult> Get([FromRoute] string username)

-        {

-            try

-            {

-                var detail = await _service.GetUserDetail(username);

-                return Ok(detail);

-            }

-            catch (UserNotExistException)

-            {

-                return NotFound(new CommonResponse(ErrorCodes.Get_UserNotExist, "The user does not exist."));

-            }

-        }

-

-        [HttpPatch("details")]

-        [Authorize]

-        [ProducesResponseType(StatusCodes.Status200OK, Type = typeof(void))]

-        [ProducesResponseType(StatusCodes.Status400BadRequest)]

-        [ProducesResponseType(StatusCodes.Status403Forbidden)]

-        [ProducesResponseType(StatusCodes.Status404NotFound)]

-        public async Task<IActionResult> Patch([FromRoute] string username, [FromBody] UserDetail detail)

-        {

-            if (!User.IsAdmin() && User.Identity.Name != username)

-                return StatusCode(StatusCodes.Status403Forbidden, new CommonResponse(ErrorCodes.Patch_Forbid, "You can't change other's details unless you are admin."));

-

-            try

-            {

-                await _service.UpdateUserDetail(username, detail);

-                return Ok();

-            }

-            catch (UserNotExistException)

-            {

-                return NotFound(new CommonResponse(ErrorCodes.Patch_UserNotExist, "The user does not exist."));

-            }

-        }

-    }

-}

diff --git a/Timeline/Entities/DatabaseContext.cs b/Timeline/Entities/DatabaseContext.cs
index d9815660..e1b98e7d 100644
--- a/Timeline/Entities/DatabaseContext.cs
+++ b/Timeline/Entities/DatabaseContext.cs
@@ -1,38 +1,7 @@
 using Microsoft.EntityFrameworkCore;

-using System.ComponentModel.DataAnnotations;

-using System.ComponentModel.DataAnnotations.Schema;

 

 namespace Timeline.Entities

 {

-    public static class UserRoles

-    {

-        public const string Admin = "admin";

-        public const string User = "user";

-    }

-

-    [Table("users")]

-    public class User

-    {

-        [Column("id"), Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]

-        public long Id { get; set; }

-

-        [Column("name"), MaxLength(26), Required]

-        public string Name { get; set; }

-

-        [Column("password"), Required]

-        public string EncryptedPassword { get; set; }

-

-        [Column("roles"), Required]

-        public string RoleString { get; set; }

-

-        [Column("version"), Required]

-        public long Version { get; set; }

-

-        public UserAvatar Avatar { get; set; }

-

-        public UserDetailEntity Detail { get; set; }

-    }

-

     public class DatabaseContext : DbContext

     {

         public DatabaseContext(DbContextOptions<DatabaseContext> options)

@@ -41,14 +10,14 @@ namespace Timeline.Entities
 

         }

 

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods")]

         protected override void OnModelCreating(ModelBuilder modelBuilder)

         {

             modelBuilder.Entity<User>().Property(e => e.Version).HasDefaultValue(0);

             modelBuilder.Entity<User>().HasIndex(e => e.Name).IsUnique();

         }

 

-        public DbSet<User> Users { get; set; }

-        public DbSet<UserAvatar> UserAvatars { get; set; }

-        public DbSet<UserDetailEntity> UserDetails { get; set; }

+        public DbSet<User> Users { get; set; } = default!;

+        public DbSet<UserAvatar> UserAvatars { get; set; } = default!;

     }

 }

diff --git a/Timeline/Entities/User.cs b/Timeline/Entities/User.cs
new file mode 100644
index 00000000..6e8e4967
--- /dev/null
+++ b/Timeline/Entities/User.cs
@@ -0,0 +1,32 @@
+using System.ComponentModel.DataAnnotations;

+using System.ComponentModel.DataAnnotations.Schema;

+

+namespace Timeline.Entities

+{

+    public static class UserRoles

+    {

+        public const string Admin = "admin";

+        public const string User = "user";

+    }

+

+    [Table("users")]

+    public class User

+    {

+        [Column("id"), Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]

+        public long Id { get; set; }

+

+        [Column("name"), MaxLength(26), Required]

+        public string Name { get; set; } = default!;

+

+        [Column("password"), Required]

+        public string EncryptedPassword { get; set; } = default!;

+

+        [Column("roles"), Required]

+        public string RoleString { get; set; } = default!;

+

+        [Column("version"), Required]

+        public long Version { get; set; }

+

+        public UserAvatar? Avatar { get; set; }

+    }

+}

diff --git a/Timeline/Entities/UserAvatar.cs b/Timeline/Entities/UserAvatar.cs
index d549aea5..a5b18b94 100644
--- a/Timeline/Entities/UserAvatar.cs
+++ b/Timeline/Entities/UserAvatar.cs
@@ -11,29 +11,18 @@ namespace Timeline.Entities
         public long Id { get; set; }

 

         [Column("data")]

-        public byte[] Data { get; set; }

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Performance", "CA1819:Properties should not return arrays", Justification = "This is data base entity.")]

+        public byte[]? Data { get; set; }

 

         [Column("type")]

-        public string Type { get; set; }

+        public string? Type { get; set; }

 

         [Column("etag"), MaxLength(30)]

-        public string ETag { get; set; }

+        public string? ETag { get; set; }

 

         [Column("last_modified"), Required]

         public DateTime LastModified { get; set; }

 

         public long UserId { get; set; }

-

-        public static UserAvatar Create(DateTime lastModified)

-        {

-            return new UserAvatar

-            {

-                Id = 0,

-                Data = null,

-                Type = null,

-                ETag = null,

-                LastModified = lastModified

-            };

-        }

     }

 }

diff --git a/Timeline/Entities/UserDetail.cs b/Timeline/Entities/UserDetail.cs
deleted file mode 100644
index bc14dbe6..00000000
--- a/Timeline/Entities/UserDetail.cs
+++ /dev/null
@@ -1,29 +0,0 @@
-using System.ComponentModel.DataAnnotations;

-using System.ComponentModel.DataAnnotations.Schema;

-

-namespace Timeline.Entities

-{

-    [Table("user_details")]

-    public class UserDetailEntity

-    {

-        [Column("id"), Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]

-        public long Id { get; set; }

-

-        [Column("nickname"), MaxLength(15)]

-        public string Nickname { get; set; }

-

-        [Column("qq"), MaxLength(15)]

-        public string QQ { get; set; }

-

-        [Column("email"), MaxLength(50)]

-        public string Email { get; set; }

-

-        [Column("phone_number"), MaxLength(15)]

-        public string PhoneNumber { get; set; }

-

-        [Column("description")]

-        public string Description { get; set; }

-

-        public long UserId { get; set; }

-    }

-}

diff --git a/Timeline/ErrorCodes.cs b/Timeline/ErrorCodes.cs
new file mode 100644
index 00000000..5e7f003a
--- /dev/null
+++ b/Timeline/ErrorCodes.cs
@@ -0,0 +1,36 @@
+namespace Timeline

+{

+    /// <summary>

+    /// All error code constants.

+    /// </summary>

+    /// <remarks>

+    /// Scheme:

+    /// abbbccdd

+    /// </remarks>

+    public static partial class ErrorCodes

+    {

+        public static partial class Http // a = 1 

+        {

+            public static class Common // bbb = 000

+            {

+                public const int InvalidModel = 10000000;

+

+                public static class Header // cc = 01

+                {

+                    public const int Missing_ContentType = 10000101; // dd = 01

+                    public const int Missing_ContentLength = 10000102; // dd = 02

+                    public const int Zero_ContentLength = 10000103; // dd = 03

+                    public const int BadFormat_IfNonMatch = 10000104; // dd = 04

+                }

+

+                public static class Content // cc = 02

+                {

+                    public const int TooBig = 1000201;

+                    public const int UnmatchedLength_Smaller = 10030202;

+                    public const int UnmatchedLength_Bigger = 10030203;

+                }

+            }

+        }

+

+    }

+}

diff --git a/Timeline/Filters/ContentHeaderAttributes.cs b/Timeline/Filters/ContentHeaderAttributes.cs
index 14685a01..e3d4eeb2 100644
--- a/Timeline/Filters/ContentHeaderAttributes.cs
+++ b/Timeline/Filters/ContentHeaderAttributes.cs
@@ -1,16 +1,20 @@
 using Microsoft.AspNetCore.Mvc;

 using Microsoft.AspNetCore.Mvc.Filters;

+using Microsoft.Extensions.DependencyInjection;

+using Microsoft.Extensions.Localization;

 using Timeline.Models.Http;

 

 namespace Timeline.Filters

 {

     public class RequireContentTypeAttribute : ActionFilterAttribute

     {

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods")]

         public override void OnActionExecuting(ActionExecutingContext context)

         {

             if (context.HttpContext.Request.ContentType == null)

             {

-                context.Result = new BadRequestObjectResult(CommonResponse.MissingContentType());

+                var localizerFactory = context.HttpContext.RequestServices.GetRequiredService<IStringLocalizerFactory>();

+                context.Result = new BadRequestObjectResult(HeaderErrorResponse.MissingContentType(localizerFactory));

             }

         }

     }

@@ -30,17 +34,20 @@ namespace Timeline.Filters
 

         public bool RequireNonZero { get; set; }

 

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods")]

         public override void OnActionExecuting(ActionExecutingContext context)

         {

             if (context.HttpContext.Request.ContentLength == null)

             {

-                context.Result = new BadRequestObjectResult(CommonResponse.MissingContentLength());

+                var localizerFactory = context.HttpContext.RequestServices.GetRequiredService<IStringLocalizerFactory>();

+                context.Result = new BadRequestObjectResult(HeaderErrorResponse.MissingContentLength(localizerFactory));

                 return;

             }

 

             if (RequireNonZero && context.HttpContext.Request.ContentLength.Value == 0)

             {

-                context.Result = new BadRequestObjectResult(CommonResponse.ZeroContentLength());

+                var localizerFactory = context.HttpContext.RequestServices.GetRequiredService<IStringLocalizerFactory>();

+                context.Result = new BadRequestObjectResult(HeaderErrorResponse.ZeroContentLength(localizerFactory));

                 return;

             }

         }

diff --git a/Timeline/GlobalSuppressions.cs b/Timeline/GlobalSuppressions.cs
new file mode 100644
index 00000000..e720e5b7
--- /dev/null
+++ b/Timeline/GlobalSuppressions.cs
@@ -0,0 +1,13 @@
+// This file is used by Code Analysis to maintain SuppressMessage

+// attributes that are applied to this project.

+// Project-level suppressions either have no target or are given

+// a specific target and scoped to a namespace, type, member, etc.

+

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Reliability", "CA2007:Consider calling ConfigureAwait on the awaited task", Justification = "This is not a UI application.")]

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1034:Nested types should not be visible", Justification = "This is not bad.")]

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods", Justification = "No need to check the null because it's ASP.Net's duty.", Scope = "namespaceanddescendants", Target = "Timeline.Controllers")]

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods", Justification = "Migrations code are auto generated.", Scope = "namespaceanddescendants", Target = "Timeline.Migrations")]

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Naming", "CA1707:Identifiers should not contain underscores", Justification = "Error code constant identifiers.", Scope = "type", Target = "Timeline.ErrorCodes")]

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Naming", "CA1716:Identifiers should not match keywords", Justification = "Error code constant identifiers.", Scope = "type", Target = "Timeline.ErrorCodes")]

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Naming", "CA1724:Type names should not match namespaces", Justification = "Error code constant identifiers.", Scope = "type", Target = "Timeline.ErrorCodes")]

+[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage("Performance", "CA1824:Mark assemblies with NeutralResourcesLanguageAttribute", Justification = "Applying this breaks the function of resources in my app.")]

diff --git a/Timeline/Helpers/InvalidModelResponseFactory.cs b/Timeline/Helpers/InvalidModelResponseFactory.cs
index c792e845..643c99ac 100644
--- a/Timeline/Helpers/InvalidModelResponseFactory.cs
+++ b/Timeline/Helpers/InvalidModelResponseFactory.cs
@@ -6,6 +6,7 @@ namespace Timeline.Helpers
 {

     public static class InvalidModelResponseFactory

     {

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods")]

         public static IActionResult Factory(ActionContext context)

         {

             var modelState = context.ModelState;

diff --git a/Timeline/Helpers/LanguageHelper.cs b/Timeline/Helpers/LanguageHelper.cs
new file mode 100644
index 00000000..b0156b8b
--- /dev/null
+++ b/Timeline/Helpers/LanguageHelper.cs
@@ -0,0 +1,12 @@
+using System.Linq;

+

+namespace Timeline.Helpers

+{

+    public static class LanguageHelper

+    {

+        public static bool AreSame(this bool firstBool, params bool[] otherBools)

+        {

+            return otherBools.All(b => b == firstBool);

+        }

+    }

+}

diff --git a/Timeline/Helpers/Log.cs b/Timeline/Helpers/Log.cs
index 123e8a8e..68c975fa 100644
--- a/Timeline/Helpers/Log.cs
+++ b/Timeline/Helpers/Log.cs
@@ -3,20 +3,19 @@ using System.Text;
 

 namespace Timeline.Helpers

 {

-    public static class MyLogHelper

+    public static class Log

     {

-        public static KeyValuePair<string, object> Pair(string key, object value) => new KeyValuePair<string, object>(key, value);

-

-        public static string FormatLogMessage(string summary, params KeyValuePair<string, object>[] properties)

+        public static string Format(string summary, params (string, object?)[] properties)

         {

             var builder = new StringBuilder();

             builder.Append(summary);

             foreach (var property in properties)

             {

+                var (key, value) = property;

                 builder.AppendLine();

-                builder.Append(property.Key);

+                builder.Append(key);

                 builder.Append(" : ");

-                builder.Append(property.Value);

+                builder.Append(value);

             }

             return builder.ToString();

         }

diff --git a/Timeline/Helpers/StringLocalizerFactoryExtensions.cs b/Timeline/Helpers/StringLocalizerFactoryExtensions.cs
new file mode 100644
index 00000000..c2252b2c
--- /dev/null
+++ b/Timeline/Helpers/StringLocalizerFactoryExtensions.cs
@@ -0,0 +1,19 @@
+

+using Microsoft.Extensions.Localization;

+using System.Reflection;

+

+namespace Timeline.Helpers

+{

+    internal static class StringLocalizerFactoryExtensions

+    {

+        internal static IStringLocalizer Create(this IStringLocalizerFactory factory, string basename)

+        {

+            return factory.Create(basename, new AssemblyName(typeof(StringLocalizerFactoryExtensions).Assembly.FullName!).Name);

+        }

+

+        internal static StringLocalizer<T> Create<T>(this IStringLocalizerFactory factory)

+        {

+            return new StringLocalizer<T>(factory);

+        }

+    }

+}
\ No newline at end of file
diff --git a/Timeline/InvalidBranchException.cs b/Timeline/InvalidBranchException.cs
new file mode 100644
index 00000000..32937c5d
--- /dev/null
+++ b/Timeline/InvalidBranchException.cs
@@ -0,0 +1,16 @@
+using System;

+

+namespace Timeline

+{

+

+    [Serializable]

+    public class InvalidBranchException : Exception

+    {

+        public InvalidBranchException() : base(Resources.Common.ExceptionInvalidBranch) { }

+        public InvalidBranchException(string message) : base(message) { }

+        public InvalidBranchException(string message, Exception inner) : base(message, inner) { }

+        protected InvalidBranchException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+    }

+}

diff --git a/Timeline/Migrations/20190822072156_AddUserDetail.Designer.cs b/Timeline/Migrations/20190822072156_AddUserDetail.Designer.cs
deleted file mode 100644
index 2bbcf673..00000000
--- a/Timeline/Migrations/20190822072156_AddUserDetail.Designer.cs
+++ /dev/null
@@ -1,136 +0,0 @@
-// <auto-generated />

-using System;

-using Microsoft.EntityFrameworkCore;

-using Microsoft.EntityFrameworkCore.Infrastructure;

-using Microsoft.EntityFrameworkCore.Migrations;

-using Microsoft.EntityFrameworkCore.Storage.ValueConversion;

-using Timeline.Entities;

-

-namespace Timeline.Migrations

-{

-    [DbContext(typeof(DatabaseContext))]

-    [Migration("20190822072156_AddUserDetail")]

-    partial class AddUserDetail

-    {

-        protected override void BuildTargetModel(ModelBuilder modelBuilder)

-        {

-#pragma warning disable 612, 618

-            modelBuilder

-                .HasAnnotation("ProductVersion", "2.2.6-servicing-10079")

-                .HasAnnotation("Relational:MaxIdentifierLength", 64);

-

-            modelBuilder.Entity("Timeline.Entities.User", b =>

-                {

-                    b.Property<long>("Id")

-                        .ValueGeneratedOnAdd()

-                        .HasColumnName("id");

-

-                    b.Property<string>("EncryptedPassword")

-                        .IsRequired()

-                        .HasColumnName("password");

-

-                    b.Property<string>("Name")

-                        .IsRequired()

-                        .HasColumnName("name")

-                        .HasMaxLength(26);

-

-                    b.Property<string>("RoleString")

-                        .IsRequired()

-                        .HasColumnName("roles");

-

-                    b.Property<long>("Version")

-                        .ValueGeneratedOnAdd()

-                        .HasColumnName("version")

-                        .HasDefaultValue(0L);

-

-                    b.HasKey("Id");

-

-                    b.HasIndex("Name")

-                        .IsUnique();

-

-                    b.ToTable("users");

-                });

-

-            modelBuilder.Entity("Timeline.Entities.UserAvatar", b =>

-                {

-                    b.Property<long>("Id")

-                        .ValueGeneratedOnAdd()

-                        .HasColumnName("id");

-

-                    b.Property<byte[]>("Data")

-                        .HasColumnName("data");

-

-                    b.Property<string>("ETag")

-                        .HasColumnName("etag")

-                        .HasMaxLength(30);

-

-                    b.Property<DateTime>("LastModified")

-                        .HasColumnName("last_modified");

-

-                    b.Property<string>("Type")

-                        .HasColumnName("type");

-

-                    b.Property<long>("UserId");

-

-                    b.HasKey("Id");

-

-                    b.HasIndex("UserId")

-                        .IsUnique();

-

-                    b.ToTable("user_avatars");

-                });

-

-            modelBuilder.Entity("Timeline.Entities.UserDetailEntity", b =>

-                {

-                    b.Property<long>("Id")

-                        .ValueGeneratedOnAdd()

-                        .HasColumnName("id");

-

-                    b.Property<string>("Description")

-                        .HasColumnName("description");

-

-                    b.Property<string>("EMail")

-                        .HasColumnName("email")

-                        .HasMaxLength(50);

-

-                    b.Property<string>("Nickname")

-                        .HasColumnName("nickname")

-                        .HasMaxLength(15);

-

-                    b.Property<string>("PhoneNumber")

-                        .HasColumnName("phone_number")

-                        .HasMaxLength(15);

-

-                    b.Property<string>("QQ")

-                        .HasColumnName("qq")

-                        .HasMaxLength(15);

-

-                    b.Property<long>("UserId");

-

-                    b.HasKey("Id");

-

-                    b.HasIndex("UserId")

-                        .IsUnique();

-

-                    b.ToTable("user_details");

-                });

-

-            modelBuilder.Entity("Timeline.Entities.UserAvatar", b =>

-                {

-                    b.HasOne("Timeline.Entities.User")

-                        .WithOne("Avatar")

-                        .HasForeignKey("Timeline.Entities.UserAvatar", "UserId")

-                        .OnDelete(DeleteBehavior.Cascade);

-                });

-

-            modelBuilder.Entity("Timeline.Entities.UserDetailEntity", b =>

-                {

-                    b.HasOne("Timeline.Entities.User")

-                        .WithOne("Detail")

-                        .HasForeignKey("Timeline.Entities.UserDetailEntity", "UserId")

-                        .OnDelete(DeleteBehavior.Cascade);

-                });

-#pragma warning restore 612, 618

-        }

-    }

-}

diff --git a/Timeline/Migrations/20190822072156_AddUserDetail.cs b/Timeline/Migrations/20190822072156_AddUserDetail.cs
deleted file mode 100644
index 4aa6446b..00000000
--- a/Timeline/Migrations/20190822072156_AddUserDetail.cs
+++ /dev/null
@@ -1,47 +0,0 @@
-using Microsoft.EntityFrameworkCore.Metadata;

-using Microsoft.EntityFrameworkCore.Migrations;

-

-namespace Timeline.Migrations

-{

-    public partial class AddUserDetail : Migration

-    {

-        protected override void Up(MigrationBuilder migrationBuilder)

-        {

-            migrationBuilder.CreateTable(

-                name: "user_details",

-                columns: table => new

-                {

-                    id = table.Column<long>(nullable: false)

-                        .Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn),

-                    nickname = table.Column<string>(maxLength: 15, nullable: true),

-                    qq = table.Column<string>(maxLength: 15, nullable: true),

-                    email = table.Column<string>(maxLength: 50, nullable: true),

-                    phone_number = table.Column<string>(maxLength: 15, nullable: true),

-                    description = table.Column<string>(nullable: true),

-                    UserId = table.Column<long>(nullable: false)

-                },

-                constraints: table =>

-                {

-                    table.PrimaryKey("PK_user_details", x => x.id);

-                    table.ForeignKey(

-                        name: "FK_user_details_users_UserId",

-                        column: x => x.UserId,

-                        principalTable: "users",

-                        principalColumn: "id",

-                        onDelete: ReferentialAction.Cascade);

-                });

-

-            migrationBuilder.CreateIndex(

-                name: "IX_user_details_UserId",

-                table: "user_details",

-                column: "UserId",

-                unique: true);

-        }

-

-        protected override void Down(MigrationBuilder migrationBuilder)

-        {

-            migrationBuilder.DropTable(

-                name: "user_details");

-        }

-    }

-}

diff --git a/Timeline/Models/Http/Common.cs b/Timeline/Models/Http/Common.cs
index a72f187c..39ddddd9 100644
--- a/Timeline/Models/Http/Common.cs
+++ b/Timeline/Models/Http/Common.cs
@@ -1,76 +1,164 @@
+using Microsoft.Extensions.Localization;

+using Timeline.Helpers;

+

 namespace Timeline.Models.Http

 {

     public class CommonResponse

     {

-        public static class ErrorCodes

+        internal static CommonResponse InvalidModel(string message)

+        {

+            return new CommonResponse(ErrorCodes.Http.Common.InvalidModel, message);

+        }

+

+        public CommonResponse()

         {

-            /// <summary>

-            /// Used when the model is invaid.

-            /// For example a required field is null.

-            /// </summary>

-            public const int InvalidModel = -100;

 

-            public const int Header_Missing_ContentType = -111;

-            public const int Header_Missing_ContentLength = -112;

-            public const int Header_Zero_ContentLength = -113;

-            public const int Header_BadFormat_IfNonMatch = -114;

         }

 

-        public static CommonResponse InvalidModel(string message)

+        public CommonResponse(int code, string message)

         {

-            return new CommonResponse(ErrorCodes.InvalidModel, message);

+            Code = code;

+            Message = message;

         }

 

-        public static CommonResponse MissingContentType()

+        public int Code { get; set; }

+        public string? Message { get; set; }

+    }

+

+    internal static class HeaderErrorResponse

+    {

+        internal static CommonResponse MissingContentType(IStringLocalizerFactory localizerFactory)

         {

-            return new CommonResponse(ErrorCodes.Header_Missing_ContentType, "Header Content-Type is required.");

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonResponse(ErrorCodes.Http.Common.Header.Missing_ContentType, localizer["HeaderMissingContentType"]);

         }

 

-        public static CommonResponse MissingContentLength()

+        internal static CommonResponse MissingContentLength(IStringLocalizerFactory localizerFactory)

         {

-            return new CommonResponse(ErrorCodes.Header_Missing_ContentLength, "Header Content-Length is missing or of bad format.");

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonResponse(ErrorCodes.Http.Common.Header.Missing_ContentLength, localizer["HeaderMissingContentLength"]);

         }

 

-        public static CommonResponse ZeroContentLength()

+        internal static CommonResponse ZeroContentLength(IStringLocalizerFactory localizerFactory)

         {

-            return new CommonResponse(ErrorCodes.Header_Zero_ContentLength, "Header Content-Length must not be 0.");

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonResponse(ErrorCodes.Http.Common.Header.Zero_ContentLength, localizer["HeaderZeroContentLength"]);

         }

 

-        public static CommonResponse BadIfNonMatch()

+        internal static CommonResponse BadIfNonMatch(IStringLocalizerFactory localizerFactory)

         {

-            return new CommonResponse(ErrorCodes.Header_BadFormat_IfNonMatch, "Header If-Non-Match is of bad format.");

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonResponse(ErrorCodes.Http.Common.Header.BadFormat_IfNonMatch, localizer["HeaderBadIfNonMatch"]);

         }

+    }

 

-        public CommonResponse()

+    internal static class ContentErrorResponse

+    {

+        internal static CommonResponse TooBig(IStringLocalizerFactory localizerFactory, string maxLength)

+        {

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonResponse(ErrorCodes.Http.Common.Content.TooBig, localizer["ContentTooBig", maxLength]);

+        }

+

+        internal static CommonResponse UnmatchedLength_Smaller(IStringLocalizerFactory localizerFactory)

+        {

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonResponse(ErrorCodes.Http.Common.Content.UnmatchedLength_Smaller, localizer["ContentUnmatchedLengthSmaller"]);

+        }

+        internal static CommonResponse UnmatchedLength_Bigger(IStringLocalizerFactory localizerFactory)

+        {

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonResponse(ErrorCodes.Http.Common.Content.UnmatchedLength_Bigger, localizer["ContentUnmatchedLengthBigger"]);

+        }

+    }

+

+

+    public class CommonDataResponse<T> : CommonResponse

+    {

+        public CommonDataResponse()

         {

 

         }

 

-        public CommonResponse(int code, string message)

+        public CommonDataResponse(int code, string message, T data)

+            : base(code, message)

         {

-            Code = code;

-            Message = message;

+            Data = data;

         }

 

-        public int Code { get; set; }

-        public string Message { get; set; }

+        public T Data { get; set; } = default!;

     }

 

-    public static class CommonPutResponse

+    public class CommonPutResponse : CommonDataResponse<CommonPutResponse.ResponseData>

     {

-        public const int CreatedCode = 0;

-        public const int ModifiedCode = 1;

+        public class ResponseData

+        {

+            public ResponseData(bool create)

+            {

+                Create = create;

+            }

 

-        public static CommonResponse Created { get; } = new CommonResponse(CreatedCode, "A new item is created.");

-        public static CommonResponse Modified { get; } = new CommonResponse(ModifiedCode, "An existent item is modified.");

+            public bool Create { get; set; }

+        }

+

+        public CommonPutResponse()

+        {

+

+        }

+

+        public CommonPutResponse(int code, string message, bool create)

+            : base(code, message, new ResponseData(create))

+        {

+

+        }

+

+        internal static CommonPutResponse Create(IStringLocalizerFactory localizerFactory)

+        {

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonPutResponse(0, localizer["PutCreate"], true);

+        }

+

+        internal static CommonPutResponse Modify(IStringLocalizerFactory localizerFactory)

+        {

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonPutResponse(0, localizer["PutModify"], false);

+

+        }

     }

 

-    public static class CommonDeleteResponse

+    public class CommonDeleteResponse : CommonDataResponse<CommonDeleteResponse.ResponseData>

     {

-        public const int DeletedCode = 0;

-        public const int NotExistsCode = 1;

+        public class ResponseData

+        {

+            public ResponseData(bool delete)

+            {

+                Delete = delete;

+            }

 

-        public static CommonResponse Deleted { get; } = new CommonResponse(DeletedCode, "An existent item is deleted.");

-        public static CommonResponse NotExists { get; } = new CommonResponse(NotExistsCode, "The item does not exist.");

+            public bool Delete { get; set; }

+        }

+

+        public CommonDeleteResponse()

+        {

+

+        }

+

+        public CommonDeleteResponse(int code, string message, bool delete)

+            : base(code, message, new ResponseData(delete))

+        {

+

+        }

+

+        internal static CommonDeleteResponse Delete(IStringLocalizerFactory localizerFactory)

+        {

+            var localizer = localizerFactory.Create("Models.Http.Common");

+            return new CommonDeleteResponse(0, localizer["DeleteDelete"], true);

+        }

+

+        internal static CommonDeleteResponse NotExist(IStringLocalizerFactory localizerFactory)

+        {

+            var localizer = localizerFactory.Create("Models.Models.Http.Common");

+            return new CommonDeleteResponse(0, localizer["DeleteNotExist"], false);

+        }

     }

 }

diff --git a/Timeline/Models/Http/Token.cs b/Timeline/Models/Http/Token.cs
index 68a66d0a..ea8b59ed 100644
--- a/Timeline/Models/Http/Token.cs
+++ b/Timeline/Models/Http/Token.cs
@@ -5,28 +5,28 @@ namespace Timeline.Models.Http
     public class CreateTokenRequest

     {

         [Required]

-        public string Username { get; set; }

+        public string Username { get; set; } = default!;

         [Required]

-        public string Password { get; set; }

+        public string Password { get; set; } = default!;

         // in days, optional

         [Range(1, 365)]

-        public int? ExpireOffset { get; set; }

+        public int? Expire { get; set; }

     }

 

     public class CreateTokenResponse

     {

-        public string Token { get; set; }

-        public UserInfo User { get; set; }

+        public string Token { get; set; } = default!;

+        public UserInfo User { get; set; } = default!;

     }

 

     public class VerifyTokenRequest

     {

         [Required]

-        public string Token { get; set; }

+        public string Token { get; set; } = default!;

     }

 

     public class VerifyTokenResponse

     {

-        public UserInfo User { get; set; }

+        public UserInfo User { get; set; } = default!;

     }

 }

diff --git a/Timeline/Models/Http/User.cs b/Timeline/Models/Http/User.cs
index 4308a19c..516c1329 100644
--- a/Timeline/Models/Http/User.cs
+++ b/Timeline/Models/Http/User.cs
@@ -6,31 +6,33 @@ namespace Timeline.Models.Http
     public class UserPutRequest

     {

         [Required]

-        public string Password { get; set; }

+        public string Password { get; set; } = default!;

         [Required]

         public bool? Administrator { get; set; }

     }

 

     public class UserPatchRequest

     {

-        public string Password { get; set; }

+        public string? Password { get; set; }

         public bool? Administrator { get; set; }

     }

 

     public class ChangeUsernameRequest

     {

         [Required]

-        public string OldUsername { get; set; }

+        [Username]

+        public string OldUsername { get; set; } = default!;

 

-        [Required, ValidateWith(typeof(UsernameValidator))]

-        public string NewUsername { get; set; }

+        [Required]

+        [Username]

+        public string NewUsername { get; set; } = default!;

     }

 

     public class ChangePasswordRequest

     {

         [Required]

-        public string OldPassword { get; set; }

+        public string OldPassword { get; set; } = default!;

         [Required]

-        public string NewPassword { get; set; }

+        public string NewPassword { get; set; } = default!;

     }

 }

diff --git a/Timeline/Models/PutResult.cs b/Timeline/Models/PutResult.cs
index 544602eb..cecf86e6 100644
--- a/Timeline/Models/PutResult.cs
+++ b/Timeline/Models/PutResult.cs
@@ -8,10 +8,10 @@ namespace Timeline.Models
         /// <summary>

         /// Indicates the item did not exist and now is created.

         /// </summary>

-        Created,

+        Create,

         /// <summary>

         /// Indicates the item exists already and is modified.

         /// </summary>

-        Modified

+        Modify

     }

 }

diff --git a/Timeline/Models/UserConvert.cs b/Timeline/Models/UserConvert.cs
new file mode 100644
index 00000000..5b132421
--- /dev/null
+++ b/Timeline/Models/UserConvert.cs
@@ -0,0 +1,67 @@
+using System;

+using System.Collections.Generic;

+using System.Linq;

+using Timeline.Entities;

+using Timeline.Services;

+

+namespace Timeline.Models

+{

+    public static class UserConvert

+    {

+        public static UserInfo CreateUserInfo(User user)

+        {

+            if (user == null)

+                throw new ArgumentNullException(nameof(user));

+            return new UserInfo(user.Name, UserRoleConvert.ToBool(user.RoleString));

+        }

+

+        internal static UserCache CreateUserCache(User user)

+        {

+            if (user == null)

+                throw new ArgumentNullException(nameof(user));

+            return new UserCache

+            {

+                Username = user.Name,

+                Administrator = UserRoleConvert.ToBool(user.RoleString),

+                Version = user.Version

+            };

+        }

+    }

+

+    [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods", Justification = "No need.")]

+    public static class UserRoleConvert

+    {

+        public const string UserRole = UserRoles.User;

+        public const string AdminRole = UserRoles.Admin;

+

+        public static string[] ToArray(bool administrator)

+        {

+            return administrator ? new string[] { UserRole, AdminRole } : new string[] { UserRole };

+        }

+

+        public static string[] ToArray(string s)

+        {

+            return s.Split(',').ToArray();

+        }

+

+        public static bool ToBool(IReadOnlyCollection<string> roles)

+        {

+            return roles.Contains(AdminRole);

+        }

+

+        public static string ToString(IReadOnlyCollection<string> roles)

+        {

+            return string.Join(',', roles);

+        }

+

+        public static string ToString(bool administrator)

+        {

+            return administrator ? UserRole + "," + AdminRole : UserRole;

+        }

+

+        public static bool ToBool(string s)

+        {

+            return s.Contains("admin", StringComparison.InvariantCulture);

+        }

+    }

+}

diff --git a/Timeline/Models/UserDetail.cs b/Timeline/Models/UserDetail.cs
deleted file mode 100644
index 1a6c0c6a..00000000
--- a/Timeline/Models/UserDetail.cs
+++ /dev/null
@@ -1,45 +0,0 @@
-using System.ComponentModel.DataAnnotations;

-using Timeline.Entities;

-using Timeline.Models.Validation;

-using Newtonsoft.Json;

-

-namespace Timeline.Models

-{

-    public class UserDetail

-    {

-        [MaxLength(10)]

-        public string Nickname { get; set; }

-

-        [ValidateWith(typeof(UserDetailValidators.QQValidator))]

-        [JsonProperty(PropertyName = "qq")]

-        public string QQ { get; set; }

-

-        [ValidateWith(typeof(UserDetailValidators.EMailValidator))]

-        public string Email { get; set; }

-

-        [ValidateWith(typeof(UserDetailValidators.PhoneNumberValidator))]

-        public string PhoneNumber { get; set; }

-

-        public string Description { get; set; }

-

-        private static string CoerceEmptyToNull(string value)

-        {

-            if (string.IsNullOrEmpty(value))

-                return null;

-            else

-                return value;

-        }

-

-        public static UserDetail From(UserDetailEntity entity)

-        {

-            return new UserDetail

-            {

-                Nickname = CoerceEmptyToNull(entity.Nickname),

-                QQ = CoerceEmptyToNull(entity.QQ),

-                Email = CoerceEmptyToNull(entity.Email),

-                PhoneNumber = CoerceEmptyToNull(entity.PhoneNumber),

-                Description = CoerceEmptyToNull(entity.Description)

-            };

-        }

-    }

-}

diff --git a/Timeline/Models/UserInfo.cs b/Timeline/Models/UserInfo.cs
index e502855b..b60bdfa2 100644
--- a/Timeline/Models/UserInfo.cs
+++ b/Timeline/Models/UserInfo.cs
@@ -12,8 +12,8 @@ namespace Timeline.Models
             Administrator = administrator;

         }

 

-        public string Username { get; set; }

-        public bool Administrator { get; set; }

+        public string Username { get; set; } = default!;

+        public bool Administrator { get; set; } = default!;

 

         public override string ToString()

         {

diff --git a/Timeline/Models/UserUtility.cs b/Timeline/Models/UserUtility.cs
deleted file mode 100644
index 405987b5..00000000
--- a/Timeline/Models/UserUtility.cs
+++ /dev/null
@@ -1,60 +0,0 @@
-using System;

-using System.Linq;

-using Timeline.Entities;

-using Timeline.Services;

-

-namespace Timeline.Models

-{

-    public static class UserUtility

-    {

-        public const string UserRole = UserRoles.User;

-        public const string AdminRole = UserRoles.Admin;

-

-        public static string[] UserRoleArray { get; } = new string[] { UserRole };

-        public static string[] AdminRoleArray { get; } = new string[] { UserRole, AdminRole };

-

-        public static string[] IsAdminToRoleArray(bool isAdmin)

-        {

-            return isAdmin ? AdminRoleArray : UserRoleArray;

-        }

-

-        public static bool RoleArrayToIsAdmin(string[] roles)

-        {

-            return roles.Contains(AdminRole);

-        }

-

-        public static string[] RoleStringToRoleArray(string roleString)

-        {

-            return roleString.Split(',').ToArray();

-        }

-

-        public static string RoleArrayToRoleString(string[] roles)

-        {

-            return string.Join(',', roles);

-        }

-

-        public static string IsAdminToRoleString(bool isAdmin)

-        {

-            return RoleArrayToRoleString(IsAdminToRoleArray(isAdmin));

-        }

-

-        public static bool RoleStringToIsAdmin(string roleString)

-        {

-            return RoleArrayToIsAdmin(RoleStringToRoleArray(roleString));

-        }

-

-        public static UserInfo CreateUserInfo(User user)

-        {

-            if (user == null)

-                throw new ArgumentNullException(nameof(user));

-            return new UserInfo(user.Name, RoleStringToIsAdmin(user.RoleString));

-        }

-

-        internal static UserCache CreateUserCache(User user)

-        {

-            if (user == null)

-                throw new ArgumentNullException(nameof(user));

-            return new UserCache { Username = user.Name, Administrator = RoleStringToIsAdmin(user.RoleString), Version = user.Version };

-        }

-    }

-}

diff --git a/Timeline/Models/Validation/UserDetailValidator.cs b/Timeline/Models/Validation/UserDetailValidator.cs
deleted file mode 100644
index 19c82edb..00000000
--- a/Timeline/Models/Validation/UserDetailValidator.cs
+++ /dev/null
@@ -1,116 +0,0 @@
-using System;

-using System.Net.Mail;

-

-namespace Timeline.Models.Validation

-{

-    public abstract class OptionalStringValidator : IValidator

-    {

-        public bool Validate(object value, out string message)

-        {

-            if (value == null)

-            {

-                message = ValidationConstants.SuccessMessage;

-                return true;

-            }

-

-            if (value is string s)

-            {

-                if (s.Length == 0)

-                {

-                    message = ValidationConstants.SuccessMessage;

-                    return true;

-                }

-                return DoValidate(s, out message);

-            }

-            else

-            {

-                message = "Value is not of type string.";

-                return false;

-            }

-        }

-

-        protected abstract bool DoValidate(string value, out string message);

-    }

-

-    public static class UserDetailValidators

-    {

-

-        public class QQValidator : OptionalStringValidator

-        {

-            protected override bool DoValidate(string value, out string message)

-            {

-                if (value.Length < 5)

-                {

-                    message = "QQ is too short.";

-                    return false;

-                }

-

-                if (value.Length > 11)

-                {

-                    message = "QQ is too long.";

-                    return false;

-                }

-

-                foreach (var c in value)

-                {

-                    if (!char.IsDigit(c))

-                    {

-                        message = "QQ must only contain digit.";

-                        return false;

-                    }

-                }

-

-                message = ValidationConstants.SuccessMessage;

-                return true;

-            }

-        }

-

-        public class EMailValidator : OptionalStringValidator

-        {

-            protected override bool DoValidate(string value, out string message)

-            {

-                if (value.Length > 50)

-                {

-                    message = "E-Mail is too long.";

-                    return false;

-                }

-

-                try

-                {

-                    var _ = new MailAddress(value);

-                }

-                catch (FormatException)

-                {

-                    message = "The format of E-Mail is bad.";

-                    return false;

-                }

-                message = ValidationConstants.SuccessMessage;

-                return true;

-            }

-        }

-

-        public class PhoneNumberValidator : OptionalStringValidator

-        {

-            protected override bool DoValidate(string value, out string message)

-            {

-                if (value.Length > 14)

-                {

-                    message = "Phone number is too long.";

-                    return false;

-                }

-

-                foreach (var c in value)

-                {

-                    if (!char.IsDigit(c))

-                    {

-                        message = "Phone number can only contain digit.";

-                        return false;

-                    }

-                }

-

-                message = ValidationConstants.SuccessMessage;

-                return true;

-            }

-        }

-    }

-}

diff --git a/Timeline/Models/Validation/UsernameValidator.cs b/Timeline/Models/Validation/UsernameValidator.cs
index e4891400..dc237add 100644
--- a/Timeline/Models/Validation/UsernameValidator.cs
+++ b/Timeline/Models/Validation/UsernameValidator.cs
@@ -1,45 +1,51 @@
-using System.Linq;

-using System.Text.RegularExpressions;

+using System;

+using System.Linq;

 

 namespace Timeline.Models.Validation

 {

     public class UsernameValidator : Validator<string>

     {

         public const int MaxLength = 26;

-        public const string RegexPattern = @"^[a-zA-Z0-9_][a-zA-Z0-9-_]*$";

 

-        private readonly Regex _regex = new Regex(RegexPattern);

-

-        protected override bool DoValidate(string value, out string message)

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods", Justification = "Already checked in base class.")]

+        protected override (bool, ValidationMessageGenerator) DoValidate(string value)

         {

             if (value.Length == 0)

             {

-                message = "An empty string is not permitted.";

-                return false;

+                return (false, factory =>

+                    factory?.Create(typeof(UsernameValidator))?["ValidationMessageEmptyString"]

+                    ?? Resources.Models.Validation.UsernameValidator.InvariantValidationMessageEmptyString);

             }

 

             if (value.Length > 26)

             {

-                message = $"Too long, more than 26 characters is not premitted, found {value.Length}.";

-                return false;

+                return (false, factory =>

+                    factory?.Create(typeof(UsernameValidator))?["ValidationMessageTooLong"]

+                    ?? Resources.Models.Validation.UsernameValidator.InvariantValidationMessageTooLong);

             }

 

             foreach ((char c, int i) in value.Select((c, i) => (c, i)))

-                if (char.IsWhiteSpace(c))

+            {

+                if (!(char.IsLetterOrDigit(c) || c == '-' || c == '_'))

                 {

-                    message = $"A whitespace is found at {i} . Whitespace is not permited.";

-                    return false;

+                    return (false, factory =>

+                        factory?.Create(typeof(UsernameValidator))?["ValidationMessageInvalidChar"]

+                        ?? Resources.Models.Validation.UsernameValidator.InvariantValidationMessageInvalidChar);

                 }

-

-            var match = _regex.Match(value);

-            if (!match.Success)

-            {

-                message = "Regex match failed.";

-                return false;

             }

 

-            message = ValidationConstants.SuccessMessage;

-            return true;

+            return (true, SuccessMessageGenerator);

+        }

+    }

+

+    [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter,

+        AllowMultiple = false)]

+    public class UsernameAttribute : ValidateWithAttribute

+    {

+        public UsernameAttribute()

+            : base(typeof(UsernameValidator))

+        {

+

         }

     }

 }

diff --git a/Timeline/Models/Validation/Validator.cs b/Timeline/Models/Validation/Validator.cs
index a1acbed9..d2c7c377 100644
--- a/Timeline/Models/Validation/Validator.cs
+++ b/Timeline/Models/Validation/Validator.cs
@@ -1,11 +1,21 @@
-using System;

+using Microsoft.Extensions.DependencyInjection;

+using Microsoft.Extensions.Localization;

+using System;

 using System.ComponentModel.DataAnnotations;

+using Timeline.Helpers;

 

 namespace Timeline.Models.Validation

 {

     /// <summary>

+    /// Generate a message from a localizer factory.

+    /// If localizerFactory is null, it should return a culture-invariant message.

+    /// </summary>

+    /// <param name="localizerFactory">The localizer factory. Could be null.</param>

+    /// <returns>The message.</returns>

+    public delegate string ValidationMessageGenerator(IStringLocalizerFactory? localizerFactory);

+

+    /// <summary>

     /// A validator to validate value.

-    /// See <see cref="Validate(object, out string)"/>.

     /// </summary>

     public interface IValidator

     {

@@ -13,14 +23,8 @@ namespace Timeline.Models.Validation
         /// Validate given value.

         /// </summary>

         /// <param name="value">The value to validate.</param>

-        /// <param name="message">The validation message.</param>

-        /// <returns>True if validation passed. Otherwise false.</returns>

-        bool Validate(object value, out string message);

-    }

-

-    public static class ValidationConstants

-    {

-        public const string SuccessMessage = "Validation succeeded.";

+        /// <returns>Validation success or not and the message generator.</returns>

+        (bool, ValidationMessageGenerator) Validate(object? value);

     }

 

     /// <summary>

@@ -36,27 +40,32 @@ namespace Timeline.Models.Validation
     /// </remarks>

     public abstract class Validator<T> : IValidator

     {

-        public bool Validate(object value, out string message)

+        public (bool, ValidationMessageGenerator) Validate(object? value)

         {

             if (value == null)

             {

-                message = "Value is null.";

-                return false;

+                return (false, factory =>

+                    factory?.Create("Models.Validation.Validator")?["ValidatorMessageNull"]

+                    ?? Resources.Models.Validation.Validator.InvariantValidatorMessageNull

+                );

             }

 

             if (value is T v)

             {

-

-                return DoValidate(v, out message);

+                return DoValidate(v);

             }

             else

             {

-                message = $"Value is not of type {typeof(T).Name}";

-                return false;

+                return (false, factory =>

+                    factory?.Create("Models.Validation.Validator")?["ValidatorMessageBadType", typeof(T).FullName]

+                    ?? Resources.Models.Validation.Validator.InvariantValidatorMessageBadType);

             }

         }

 

-        protected abstract bool DoValidate(T value, out string message);

+        protected static ValidationMessageGenerator SuccessMessageGenerator { get; } = factory =>

+            factory?.Create("Models.Validation.Validator")?["ValidatorMessageSuccess"] ?? Resources.Models.Validation.Validator.InvariantValidatorMessageSuccess;

+

+        protected abstract (bool, ValidationMessageGenerator) DoValidate(T value);

     }

 

     [AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter,

@@ -84,24 +93,33 @@ namespace Timeline.Models.Validation
                 throw new ArgumentNullException(nameof(validatorType));

 

             if (!typeof(IValidator).IsAssignableFrom(validatorType))

-                throw new ArgumentException("Given type is not assignable to IValidator.", nameof(validatorType));

+                throw new ArgumentException(

+                Resources.Models.Validation.Validator.ValidateWithAttributeNotValidator,

+                nameof(validatorType));

 

             try

             {

-                _validator = Activator.CreateInstance(validatorType) as IValidator;

+                _validator = (Activator.CreateInstance(validatorType) as IValidator)!;

             }

             catch (Exception e)

             {

-                throw new ArgumentException("Failed to create a validator instance from default constructor. See inner exception.", e);

+                throw new ArgumentException(

+                    Resources.Models.Validation.Validator.ValidateWithAttributeCreateFail, e);

             }

         }

 

         protected override ValidationResult IsValid(object value, ValidationContext validationContext)

         {

-            if (_validator.Validate(value, out var message))

+            var (result, messageGenerator) = _validator.Validate(value);

+            if (result)

+            {

                 return ValidationResult.Success;

+            }

             else

-                return new ValidationResult(string.Format("Field {0} is bad. {1}", validationContext.DisplayName, message));

+            {

+                var localizerFactory = validationContext.GetRequiredService<IStringLocalizerFactory>();

+                return new ValidationResult(messageGenerator(localizerFactory));

+            }

         }

     }

 }

diff --git a/Timeline/Program.cs b/Timeline/Program.cs
index dfc93b9e..4a098adf 100644
--- a/Timeline/Program.cs
+++ b/Timeline/Program.cs
@@ -3,10 +3,11 @@ using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;

 using Microsoft.Extensions.FileProviders;

 using Microsoft.Extensions.Hosting;

+using System.Resources;

 

 namespace Timeline

 {

-    public class Program

+    public static class Program

     {

         public static void Main(string[] args)

         {

diff --git a/Timeline/Resources/Authentication/AuthHandler.Designer.cs b/Timeline/Resources/Authentication/AuthHandler.Designer.cs
new file mode 100644
index 00000000..fd4540ea
--- /dev/null
+++ b/Timeline/Resources/Authentication/AuthHandler.Designer.cs
@@ -0,0 +1,99 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Authentication {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class AuthHandler {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal AuthHandler() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Authentication.AuthHandler", typeof(AuthHandler).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Token is found in authorization header. Token is {0} ..

+        /// </summary>

+        internal static string LogTokenFoundInHeader {

+            get {

+                return ResourceManager.GetString("LogTokenFoundInHeader", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Token is found in query param with key &quot;{0}&quot;. Token is {1} ..

+        /// </summary>

+        internal static string LogTokenFoundInQuery {

+            get {

+                return ResourceManager.GetString("LogTokenFoundInQuery", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to No jwt token is found..

+        /// </summary>

+        internal static string LogTokenNotFound {

+            get {

+                return ResourceManager.GetString("LogTokenNotFound", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A jwt token validation failed..

+        /// </summary>

+        internal static string LogTokenValidationFail {

+            get {

+                return ResourceManager.GetString("LogTokenValidationFail", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Authentication/AuthHandler.resx b/Timeline/Resources/Authentication/AuthHandler.resx
new file mode 100644
index 00000000..4cddc8ce
--- /dev/null
+++ b/Timeline/Resources/Authentication/AuthHandler.resx
@@ -0,0 +1,132 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="LogTokenFoundInHeader" xml:space="preserve">

+    <value>Token is found in authorization header. Token is {0} .</value>

+  </data>

+  <data name="LogTokenFoundInQuery" xml:space="preserve">

+    <value>Token is found in query param with key "{0}". Token is {1} .</value>

+  </data>

+  <data name="LogTokenNotFound" xml:space="preserve">

+    <value>No jwt token is found.</value>

+  </data>

+  <data name="LogTokenValidationFail" xml:space="preserve">

+    <value>A jwt token validation failed.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Common.Designer.cs b/Timeline/Resources/Common.Designer.cs
new file mode 100644
index 00000000..4f1c8e3f
--- /dev/null
+++ b/Timeline/Resources/Common.Designer.cs
@@ -0,0 +1,72 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class Common {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal Common() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Common", typeof(Common).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The branch is invalid. Normally this branch is not reachable..

+        /// </summary>

+        internal static string ExceptionInvalidBranch {

+            get {

+                return ResourceManager.GetString("ExceptionInvalidBranch", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Common.resx b/Timeline/Resources/Common.resx
new file mode 100644
index 00000000..8a036996
--- /dev/null
+++ b/Timeline/Resources/Common.resx
@@ -0,0 +1,123 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ExceptionInvalidBranch" xml:space="preserve">

+    <value>The branch is invalid. Normally this branch is not reachable.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/TokenController.Designer.cs b/Timeline/Resources/Controllers/TokenController.Designer.cs
new file mode 100644
index 00000000..a7c2864b
--- /dev/null
+++ b/Timeline/Resources/Controllers/TokenController.Designer.cs
@@ -0,0 +1,153 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Controllers {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class TokenController {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal TokenController() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Controllers.TokenController", typeof(TokenController).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The password is wrong..

+        /// </summary>

+        internal static string LogBadPassword {

+            get {

+                return ResourceManager.GetString("LogBadPassword", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user failed to create a token..

+        /// </summary>

+        internal static string LogCreateFailure {

+            get {

+                return ResourceManager.GetString("LogCreateFailure", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user succeeded to create a token..

+        /// </summary>

+        internal static string LogCreateSuccess {

+            get {

+                return ResourceManager.GetString("LogCreateSuccess", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The user does not exist..

+        /// </summary>

+        internal static string LogUserNotExist {

+            get {

+                return ResourceManager.GetString("LogUserNotExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The token is of bad format. It might not be created by the server..

+        /// </summary>

+        internal static string LogVerifyBadFormat {

+            get {

+                return ResourceManager.GetString("LogVerifyBadFormat", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The token is expired..

+        /// </summary>

+        internal static string LogVerifyExpire {

+            get {

+                return ResourceManager.GetString("LogVerifyExpire", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A token failed to be verified..

+        /// </summary>

+        internal static string LogVerifyFailure {

+            get {

+                return ResourceManager.GetString("LogVerifyFailure", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Token has an old version. User might have update some info..

+        /// </summary>

+        internal static string LogVerifyOldVersion {

+            get {

+                return ResourceManager.GetString("LogVerifyOldVersion", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A token succeeded to be verified..

+        /// </summary>

+        internal static string LogVerifySuccess {

+            get {

+                return ResourceManager.GetString("LogVerifySuccess", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to User does not exist. Administrator might have deleted this user..

+        /// </summary>

+        internal static string LogVerifyUserNotExist {

+            get {

+                return ResourceManager.GetString("LogVerifyUserNotExist", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Controllers/TokenController.en.resx b/Timeline/Resources/Controllers/TokenController.en.resx
new file mode 100644
index 00000000..4a3d94f9
--- /dev/null
+++ b/Timeline/Resources/Controllers/TokenController.en.resx
@@ -0,0 +1,135 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ErrorBadCredential" xml:space="preserve">

+    <value>Username or password is invalid.</value>

+  </data>

+  <data name="ErrorVerifyBadFormat" xml:space="preserve">

+    <value>The token is of bad format. It might not be created by the server.</value>

+  </data>

+  <data name="ErrorVerifyExpire" xml:space="preserve">

+    <value>The token is expired.</value>

+  </data>

+  <data name="ErrorVerifyOldVersion" xml:space="preserve">

+    <value>Token has an old version. User might have update some info.</value>

+  </data>

+  <data name="ErrorVerifyUserNotExist" xml:space="preserve">

+    <value>User does not exist. Administrator might have deleted this user.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/TokenController.resx b/Timeline/Resources/Controllers/TokenController.resx
new file mode 100644
index 00000000..683d6cc9
--- /dev/null
+++ b/Timeline/Resources/Controllers/TokenController.resx
@@ -0,0 +1,150 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="LogBadPassword" xml:space="preserve">

+    <value>The password is wrong.</value>

+  </data>

+  <data name="LogCreateFailure" xml:space="preserve">

+    <value>A user failed to create a token.</value>

+  </data>

+  <data name="LogCreateSuccess" xml:space="preserve">

+    <value>A user succeeded to create a token.</value>

+  </data>

+  <data name="LogUserNotExist" xml:space="preserve">

+    <value>The user does not exist.</value>

+  </data>

+  <data name="LogVerifyBadFormat" xml:space="preserve">

+    <value>The token is of bad format. It might not be created by the server.</value>

+  </data>

+  <data name="LogVerifyExpire" xml:space="preserve">

+    <value>The token is expired.</value>

+  </data>

+  <data name="LogVerifyFailure" xml:space="preserve">

+    <value>A token failed to be verified.</value>

+  </data>

+  <data name="LogVerifyOldVersion" xml:space="preserve">

+    <value>Token has an old version. User might have update some info.</value>

+  </data>

+  <data name="LogVerifySuccess" xml:space="preserve">

+    <value>A token succeeded to be verified.</value>

+  </data>

+  <data name="LogVerifyUserNotExist" xml:space="preserve">

+    <value>User does not exist. Administrator might have deleted this user.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/TokenController.zh.resx b/Timeline/Resources/Controllers/TokenController.zh.resx
new file mode 100644
index 00000000..51e0f25b
--- /dev/null
+++ b/Timeline/Resources/Controllers/TokenController.zh.resx
@@ -0,0 +1,135 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ErrorBadCredential" xml:space="preserve">

+    <value>用户名或密码错误。</value>

+  </data>

+  <data name="ErrorVerifyBadFormat" xml:space="preserve">

+    <value>符号格式错误。这个符号可能不是这个服务器创建的。</value>

+  </data>

+  <data name="ErrorVerifyExpire" xml:space="preserve">

+    <value>符号过期了。</value>

+  </data>

+  <data name="ErrorVerifyOldVersion" xml:space="preserve">

+    <value>符号是一个旧版本。用户可能已经更新了信息。</value>

+  </data>

+  <data name="ErrorVerifyUserNotExist" xml:space="preserve">

+    <value>用户不存在。管理员可能已经删除了这个用户。</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/UserAvatarController.Designer.cs b/Timeline/Resources/Controllers/UserAvatarController.Designer.cs
new file mode 100644
index 00000000..e6eeb1e8
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserAvatarController.Designer.cs
@@ -0,0 +1,171 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Controllers {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class UserAvatarController {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal UserAvatarController() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Controllers.UserAvatarController", typeof(UserAvatarController).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Unknown AvatarDataException.ErrorReason value..

+        /// </summary>

+        internal static string ExceptionUnknownAvatarFormatError {

+            get {

+                return ResourceManager.GetString("ExceptionUnknownAvatarFormatError", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to delete a avatar of other user as a non-admin failed..

+        /// </summary>

+        internal static string LogDeleteForbid {

+            get {

+                return ResourceManager.GetString("LogDeleteForbid", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to delete a avatar of a non-existent user failed..

+        /// </summary>

+        internal static string LogDeleteNotExist {

+            get {

+                return ResourceManager.GetString("LogDeleteNotExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Succeed to delete a avatar of a user..

+        /// </summary>

+        internal static string LogDeleteSuccess {

+            get {

+                return ResourceManager.GetString("LogDeleteSuccess", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to get a avatar with If-None-Match in bad format..

+        /// </summary>

+        internal static string LogGetBadIfNoneMatch {

+            get {

+                return ResourceManager.GetString("LogGetBadIfNoneMatch", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Returned full data for a get avatar attempt..

+        /// </summary>

+        internal static string LogGetReturnData {

+            get {

+                return ResourceManager.GetString("LogGetReturnData", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Returned NotModify for a get avatar attempt..

+        /// </summary>

+        internal static string LogGetReturnNotModify {

+            get {

+                return ResourceManager.GetString("LogGetReturnNotModify", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to get a avatar of a non-existent user failed..

+        /// </summary>

+        internal static string LogGetUserNotExist {

+            get {

+                return ResourceManager.GetString("LogGetUserNotExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to put a avatar of other user as a non-admin failed..

+        /// </summary>

+        internal static string LogPutForbid {

+            get {

+                return ResourceManager.GetString("LogPutForbid", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Succeed to put a avatar of a user..

+        /// </summary>

+        internal static string LogPutSuccess {

+            get {

+                return ResourceManager.GetString("LogPutSuccess", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to put a avatar of a bad format failed..

+        /// </summary>

+        internal static string LogPutUserBadFormat {

+            get {

+                return ResourceManager.GetString("LogPutUserBadFormat", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to put a avatar of a non-existent user failed..

+        /// </summary>

+        internal static string LogPutUserNotExist {

+            get {

+                return ResourceManager.GetString("LogPutUserNotExist", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Controllers/UserAvatarController.en.resx b/Timeline/Resources/Controllers/UserAvatarController.en.resx
new file mode 100644
index 00000000..cf92ae6d
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserAvatarController.en.resx
@@ -0,0 +1,144 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ErrorDeleteForbid" xml:space="preserve">

+    <value>Normal user can't delete other's avatar.</value>

+  </data>

+  <data name="ErrorDeleteUserNotExist" xml:space="preserve">

+    <value>User does not exist.</value>

+  </data>

+  <data name="ErrorGetUserNotExist" xml:space="preserve">

+    <value>User does not exist.</value>

+  </data>

+  <data name="ErrorPutBadFormatBadSize" xml:space="preserve">

+    <value>Image is not a square.</value>

+  </data>

+  <data name="ErrorPutBadFormatCantDecode" xml:space="preserve">

+    <value>Decoding image failed.</value>

+  </data>

+  <data name="ErrorPutBadFormatUnmatchedFormat" xml:space="preserve">

+    <value>Image format is not the one in header.</value>

+  </data>

+  <data name="ErrorPutForbid" xml:space="preserve">

+    <value>Normal user can't change other's avatar.</value>

+  </data>

+  <data name="ErrorPutUserNotExist" xml:space="preserve">

+    <value>User does not exist.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/UserAvatarController.resx b/Timeline/Resources/Controllers/UserAvatarController.resx
new file mode 100644
index 00000000..58860c83
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserAvatarController.resx
@@ -0,0 +1,156 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ExceptionUnknownAvatarFormatError" xml:space="preserve">

+    <value>Unknown AvatarDataException.ErrorReason value.</value>

+  </data>

+  <data name="LogDeleteForbid" xml:space="preserve">

+    <value>Attempt to delete a avatar of other user as a non-admin failed.</value>

+  </data>

+  <data name="LogDeleteNotExist" xml:space="preserve">

+    <value>Attempt to delete a avatar of a non-existent user failed.</value>

+  </data>

+  <data name="LogDeleteSuccess" xml:space="preserve">

+    <value>Succeed to delete a avatar of a user.</value>

+  </data>

+  <data name="LogGetBadIfNoneMatch" xml:space="preserve">

+    <value>Attempt to get a avatar with If-None-Match in bad format.</value>

+  </data>

+  <data name="LogGetReturnData" xml:space="preserve">

+    <value>Returned full data for a get avatar attempt.</value>

+  </data>

+  <data name="LogGetReturnNotModify" xml:space="preserve">

+    <value>Returned NotModify for a get avatar attempt.</value>

+  </data>

+  <data name="LogGetUserNotExist" xml:space="preserve">

+    <value>Attempt to get a avatar of a non-existent user failed.</value>

+  </data>

+  <data name="LogPutForbid" xml:space="preserve">

+    <value>Attempt to put a avatar of other user as a non-admin failed.</value>

+  </data>

+  <data name="LogPutSuccess" xml:space="preserve">

+    <value>Succeed to put a avatar of a user.</value>

+  </data>

+  <data name="LogPutUserBadFormat" xml:space="preserve">

+    <value>Attempt to put a avatar of a bad format failed.</value>

+  </data>

+  <data name="LogPutUserNotExist" xml:space="preserve">

+    <value>Attempt to put a avatar of a non-existent user failed.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/UserAvatarController.zh.resx b/Timeline/Resources/Controllers/UserAvatarController.zh.resx
new file mode 100644
index 00000000..94de1606
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserAvatarController.zh.resx
@@ -0,0 +1,144 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ErrorDeleteForbid" xml:space="preserve">

+    <value>普通用户不能删除其他用户的头像。</value>

+  </data>

+  <data name="ErrorDeleteUserNotExist" xml:space="preserve">

+    <value>用户不存在。</value>

+  </data>

+  <data name="ErrorGetUserNotExist" xml:space="preserve">

+    <value>用户不存在。</value>

+  </data>

+  <data name="ErrorPutBadFormatBadSize" xml:space="preserve">

+    <value>图片不是正方形。</value>

+  </data>

+  <data name="ErrorPutBadFormatCantDecode" xml:space="preserve">

+    <value>解码图片失败。</value>

+  </data>

+  <data name="ErrorPutBadFormatUnmatchedFormat" xml:space="preserve">

+    <value>图片格式与请求头中指示的不一样。</value>

+  </data>

+  <data name="ErrorPutForbid" xml:space="preserve">

+    <value>普通用户不能修改其他用户的头像。</value>

+  </data>

+  <data name="ErrorPutUserNotExist" xml:space="preserve">

+    <value>用户不存在。</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/UserController.Designer.cs b/Timeline/Resources/Controllers/UserController.Designer.cs
new file mode 100644
index 00000000..df9cab4c
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserController.Designer.cs
@@ -0,0 +1,171 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Controllers {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class UserController {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal UserController() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Controllers.UserController", typeof(UserController).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to change password with wrong old password failed..

+        /// </summary>

+        internal static string LogChangePasswordBadPassword {

+            get {

+                return ResourceManager.GetString("LogChangePasswordBadPassword", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user has changed password..

+        /// </summary>

+        internal static string LogChangePasswordSuccess {

+            get {

+                return ResourceManager.GetString("LogChangePasswordSuccess", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to change a user&apos;s username to a existent one failed..

+        /// </summary>

+        internal static string LogChangeUsernameAlreadyExist {

+            get {

+                return ResourceManager.GetString("LogChangeUsernameAlreadyExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to change a username of a user that does not exist failed..

+        /// </summary>

+        internal static string LogChangeUsernameNotExist {

+            get {

+                return ResourceManager.GetString("LogChangeUsernameNotExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user has changed username..

+        /// </summary>

+        internal static string LogChangeUsernameSuccess {

+            get {

+                return ResourceManager.GetString("LogChangeUsernameSuccess", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user has been deleted..

+        /// </summary>

+        internal static string LogDeleteDelete {

+            get {

+                return ResourceManager.GetString("LogDeleteDelete", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to delete a user that does not exist..

+        /// </summary>

+        internal static string LogDeleteNotExist {

+            get {

+                return ResourceManager.GetString("LogDeleteNotExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to retrieve info of a user that does not exist failed..

+        /// </summary>

+        internal static string LogGetUserNotExist {

+            get {

+                return ResourceManager.GetString("LogGetUserNotExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to patch a user that does not exist failed..

+        /// </summary>

+        internal static string LogPatchUserNotExist {

+            get {

+                return ResourceManager.GetString("LogPatchUserNotExist", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Attempt to create a user with bad username failed..

+        /// </summary>

+        internal static string LogPutBadUsername {

+            get {

+                return ResourceManager.GetString("LogPutBadUsername", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user has been created..

+        /// </summary>

+        internal static string LogPutCreate {

+            get {

+                return ResourceManager.GetString("LogPutCreate", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user has been modified..

+        /// </summary>

+        internal static string LogPutModify {

+            get {

+                return ResourceManager.GetString("LogPutModify", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Controllers/UserController.en.resx b/Timeline/Resources/Controllers/UserController.en.resx
new file mode 100644
index 00000000..0bd1dfe3
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserController.en.resx
@@ -0,0 +1,138 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ErrorChangePasswordBadPassword" xml:space="preserve">

+    <value>Old password is wrong.</value>

+  </data>

+  <data name="ErrorChangeUsernameAlreadyExist" xml:space="preserve">

+    <value>The new username {0} already exists.</value>

+  </data>

+  <data name="ErrorChangeUsernameNotExist" xml:space="preserve">

+    <value>The old username {0} does not exist.</value>

+  </data>

+  <data name="ErrorGetUserNotExist" xml:space="preserve">

+    <value>The user does not exist.</value>

+  </data>

+  <data name="ErrorPatchUserNotExist" xml:space="preserve">

+    <value>Can't patch a user that does not exist.</value>

+  </data>

+  <data name="ErrorPutBadUsername" xml:space="preserve">

+    <value>Username is of bad format.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/UserController.resx b/Timeline/Resources/Controllers/UserController.resx
new file mode 100644
index 00000000..d720d1c1
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserController.resx
@@ -0,0 +1,156 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="LogChangePasswordBadPassword" xml:space="preserve">

+    <value>Attempt to change password with wrong old password failed.</value>

+  </data>

+  <data name="LogChangePasswordSuccess" xml:space="preserve">

+    <value>A user has changed password.</value>

+  </data>

+  <data name="LogChangeUsernameAlreadyExist" xml:space="preserve">

+    <value>Attempt to change a user's username to a existent one failed.</value>

+  </data>

+  <data name="LogChangeUsernameNotExist" xml:space="preserve">

+    <value>Attempt to change a username of a user that does not exist failed.</value>

+  </data>

+  <data name="LogChangeUsernameSuccess" xml:space="preserve">

+    <value>A user has changed username.</value>

+  </data>

+  <data name="LogDeleteDelete" xml:space="preserve">

+    <value>A user has been deleted.</value>

+  </data>

+  <data name="LogDeleteNotExist" xml:space="preserve">

+    <value>Attempt to delete a user that does not exist.</value>

+  </data>

+  <data name="LogGetUserNotExist" xml:space="preserve">

+    <value>Attempt to retrieve info of a user that does not exist failed.</value>

+  </data>

+  <data name="LogPatchUserNotExist" xml:space="preserve">

+    <value>Attempt to patch a user that does not exist failed.</value>

+  </data>

+  <data name="LogPutBadUsername" xml:space="preserve">

+    <value>Attempt to create a user with bad username failed.</value>

+  </data>

+  <data name="LogPutCreate" xml:space="preserve">

+    <value>A user has been created.</value>

+  </data>

+  <data name="LogPutModify" xml:space="preserve">

+    <value>A user has been modified.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Controllers/UserController.zh.resx b/Timeline/Resources/Controllers/UserController.zh.resx
new file mode 100644
index 00000000..3556083e
--- /dev/null
+++ b/Timeline/Resources/Controllers/UserController.zh.resx
@@ -0,0 +1,138 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ErrorChangePasswordBadPassword" xml:space="preserve">

+    <value>旧密码错误。</value>

+  </data>

+  <data name="ErrorChangeUsernameAlreadyExist" xml:space="preserve">

+    <value>新用户名{0}已经存在。</value>

+  </data>

+  <data name="ErrorChangeUsernameNotExist" xml:space="preserve">

+    <value>旧用户名{0}不存在。</value>

+  </data>

+  <data name="ErrorGetUserNotExist" xml:space="preserve">

+    <value>用户不存在。</value>

+  </data>

+  <data name="ErrorPatchUserNotExist" xml:space="preserve">

+    <value>不能修改一个不存在的用户。</value>

+  </data>

+  <data name="ErrorPutBadUsername" xml:space="preserve">

+    <value>用户名格式错误。</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Http/Common.en.resx b/Timeline/Resources/Models/Http/Common.en.resx
new file mode 100644
index 00000000..10407d76
--- /dev/null
+++ b/Timeline/Resources/Models/Http/Common.en.resx
@@ -0,0 +1,153 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ContentTooBig" xml:space="preserve">

+    <value>Body is too big. It can't be bigger than {0}.</value>

+  </data>

+  <data name="ContentUnmatchedLengthBigger" xml:space="preserve">

+    <value>Actual body length is bigger than it in header.</value>

+  </data>

+  <data name="ContentUnmatchedLengthSmaller" xml:space="preserve">

+    <value>Actual body length is smaller than it in header.</value>

+  </data>

+  <data name="DeleteDelete" xml:space="preserve">

+    <value>An existent item is deleted.</value>

+  </data>

+  <data name="DeleteNotExist" xml:space="preserve">

+    <value>The item does not exist, so nothing is changed.</value>

+  </data>

+  <data name="HeaderBadIfNonMatch" xml:space="preserve">

+    <value>Header If-Non-Match is of bad format.</value>

+  </data>

+  <data name="HeaderMissingContentLength" xml:space="preserve">

+    <value>Header Content-Length is missing or of bad format.</value>

+  </data>

+  <data name="HeaderMissingContentType" xml:space="preserve">

+    <value>Header Content-Type is required.</value>

+  </data>

+  <data name="HeaderZeroContentLength" xml:space="preserve">

+    <value>Header Content-Length must not be 0.</value>

+  </data>

+  <data name="PutCreate" xml:space="preserve">

+    <value>A new item is created.</value>

+  </data>

+  <data name="PutModify" xml:space="preserve">

+    <value>An existent item is modified.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Http/Common.zh.resx b/Timeline/Resources/Models/Http/Common.zh.resx
new file mode 100644
index 00000000..528dc7ab
--- /dev/null
+++ b/Timeline/Resources/Models/Http/Common.zh.resx
@@ -0,0 +1,153 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ContentTooBig" xml:space="preserve">

+    <value>请求体太大。它不能超过{0}.</value>

+  </data>

+  <data name="ContentUnmatchedLengthBigger" xml:space="preserve">

+    <value>实际的请求体长度比头中指示的大。</value>

+  </data>

+  <data name="ContentUnmatchedLengthSmaller" xml:space="preserve">

+    <value>实际的请求体长度比头中指示的小。</value>

+  </data>

+  <data name="DeleteDelete" xml:space="preserve">

+    <value>删除了一个项目。</value>

+  </data>

+  <data name="DeleteNotExist" xml:space="preserve">

+    <value>要删除的项目不存在，什么都没有修改。</value>

+  </data>

+  <data name="HeaderBadIfNonMatch" xml:space="preserve">

+    <value>头If-Non-Match格式不对。</value>

+  </data>

+  <data name="HeaderMissingContentLength" xml:space="preserve">

+    <value>头Content-Length缺失或者格式不对。</value>

+  </data>

+  <data name="HeaderMissingContentType" xml:space="preserve">

+    <value>缺少必需的头Content-Type。</value>

+  </data>

+  <data name="HeaderZeroContentLength" xml:space="preserve">

+    <value>头Content-Length不能为0。</value>

+  </data>

+  <data name="PutCreate" xml:space="preserve">

+    <value>创建了一个新项目。</value>

+  </data>

+  <data name="PutModify" xml:space="preserve">

+    <value>修改了一个已存在的项目。</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Validation/UsernameValidator.Designer.cs b/Timeline/Resources/Models/Validation/UsernameValidator.Designer.cs
new file mode 100644
index 00000000..a4c35326
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/UsernameValidator.Designer.cs
@@ -0,0 +1,90 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Models.Validation {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class UsernameValidator {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal UsernameValidator() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Models.Validation.UsernameValidator", typeof(UsernameValidator).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to An empty string is not allowed..

+        /// </summary>

+        internal static string InvariantValidationMessageEmptyString {

+            get {

+                return ResourceManager.GetString("InvariantValidationMessageEmptyString", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Invalid character, only alphabet, digit, underscore and hyphen are allowed. .

+        /// </summary>

+        internal static string InvariantValidationMessageInvalidChar {

+            get {

+                return ResourceManager.GetString("InvariantValidationMessageInvalidChar", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Too long, more than 26 characters is not premitted..

+        /// </summary>

+        internal static string InvariantValidationMessageTooLong {

+            get {

+                return ResourceManager.GetString("InvariantValidationMessageTooLong", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Models/Validation/UsernameValidator.en.resx b/Timeline/Resources/Models/Validation/UsernameValidator.en.resx
new file mode 100644
index 00000000..9171b856
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/UsernameValidator.en.resx
@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ValidationMessageEmptyString" xml:space="preserve">

+    <value>An empty string is not allowed.</value>

+  </data>

+  <data name="ValidationMessageInvalidChar" xml:space="preserve">

+    <value>Invalid character, only alphabet, digit, underscore and hyphen are allowed.</value>

+  </data>

+  <data name="ValidationMessageTooLong" xml:space="preserve">

+    <value>Too long, more than 26 characters is not premitted.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Validation/UsernameValidator.resx b/Timeline/Resources/Models/Validation/UsernameValidator.resx
new file mode 100644
index 00000000..80cae2d5
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/UsernameValidator.resx
@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="InvariantValidationMessageEmptyString" xml:space="preserve">

+    <value>An empty string is not allowed.</value>

+  </data>

+  <data name="InvariantValidationMessageInvalidChar" xml:space="preserve">

+    <value>Invalid character, only alphabet, digit, underscore and hyphen are allowed. </value>

+  </data>

+  <data name="InvariantValidationMessageTooLong" xml:space="preserve">

+    <value>Too long, more than 26 characters is not premitted.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Validation/UsernameValidator.zh.resx b/Timeline/Resources/Models/Validation/UsernameValidator.zh.resx
new file mode 100644
index 00000000..1c8a936c
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/UsernameValidator.zh.resx
@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ValidationMessageEmptyString" xml:space="preserve">

+    <value>空字符串是不允许的。</value>

+  </data>

+  <data name="ValidationMessageInvalidChar" xml:space="preserve">

+    <value>无效的字符，只能使用字母、数字、下划线和连字符。</value>

+  </data>

+  <data name="ValidationMessageTooLong" xml:space="preserve">

+    <value>太长了，不能大于26个字符。</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Validation/Validator.Designer.cs b/Timeline/Resources/Models/Validation/Validator.Designer.cs
new file mode 100644
index 00000000..4cbc13de
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/Validator.Designer.cs
@@ -0,0 +1,108 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Models.Validation {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class Validator {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal Validator() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Models.Validation.Validator", typeof(Validator).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Value is not of type {0}..

+        /// </summary>

+        internal static string InvariantValidatorMessageBadType {

+            get {

+                return ResourceManager.GetString("InvariantValidatorMessageBadType", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Value can&apos;t be null..

+        /// </summary>

+        internal static string InvariantValidatorMessageNull {

+            get {

+                return ResourceManager.GetString("InvariantValidatorMessageNull", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Validation succeeded..

+        /// </summary>

+        internal static string InvariantValidatorMessageSuccess {

+            get {

+                return ResourceManager.GetString("InvariantValidatorMessageSuccess", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Failed to create a validator instance from default constructor. See inner exception..

+        /// </summary>

+        internal static string ValidateWithAttributeCreateFail {

+            get {

+                return ResourceManager.GetString("ValidateWithAttributeCreateFail", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Given type is not assignable to IValidator..

+        /// </summary>

+        internal static string ValidateWithAttributeNotValidator {

+            get {

+                return ResourceManager.GetString("ValidateWithAttributeNotValidator", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Models/Validation/Validator.en.resx b/Timeline/Resources/Models/Validation/Validator.en.resx
new file mode 100644
index 00000000..8d2fbede
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/Validator.en.resx
@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ValidatorMessageBadType" xml:space="preserve">

+    <value>Value is not of type {0}.</value>

+  </data>

+  <data name="ValidatorMessageNull" xml:space="preserve">

+    <value>Value can't be null.</value>

+  </data>

+  <data name="ValidatorMessageSuccess" xml:space="preserve">

+    <value>Validation succeeded.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Validation/Validator.resx b/Timeline/Resources/Models/Validation/Validator.resx
new file mode 100644
index 00000000..0e8f53a6
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/Validator.resx
@@ -0,0 +1,135 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="InvariantValidatorMessageBadType" xml:space="preserve">

+    <value>Value is not of type {0}.</value>

+  </data>

+  <data name="InvariantValidatorMessageNull" xml:space="preserve">

+    <value>Value can't be null.</value>

+  </data>

+  <data name="InvariantValidatorMessageSuccess" xml:space="preserve">

+    <value>Validation succeeded.</value>

+  </data>

+  <data name="ValidateWithAttributeCreateFail" xml:space="preserve">

+    <value>Failed to create a validator instance from default constructor. See inner exception.</value>

+  </data>

+  <data name="ValidateWithAttributeNotValidator" xml:space="preserve">

+    <value>Given type is not assignable to IValidator.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Models/Validation/Validator.zh.resx b/Timeline/Resources/Models/Validation/Validator.zh.resx
new file mode 100644
index 00000000..2f98e7e3
--- /dev/null
+++ b/Timeline/Resources/Models/Validation/Validator.zh.resx
@@ -0,0 +1,129 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ValidatorMessageBadType" xml:space="preserve">

+    <value>值不是类型{0}的实例。</value>

+  </data>

+  <data name="ValidatorMessageNull" xml:space="preserve">

+    <value>值不能为null.</value>

+  </data>

+  <data name="ValidatorMessageSuccess" xml:space="preserve">

+    <value>验证成功。</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Services/Exception.Designer.cs b/Timeline/Resources/Services/Exception.Designer.cs
new file mode 100644
index 00000000..ddf60f45
--- /dev/null
+++ b/Timeline/Resources/Services/Exception.Designer.cs
@@ -0,0 +1,297 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Services {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class Exception {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal Exception() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Services.Exception", typeof(Exception).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Avartar is of bad format because {0}..

+        /// </summary>

+        internal static string AvatarFormatException {

+            get {

+                return ResourceManager.GetString("AvatarFormatException", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to image is not a square, aka, width is not equal to height.

+        /// </summary>

+        internal static string AvatarFormatExceptionBadSize {

+            get {

+                return ResourceManager.GetString("AvatarFormatExceptionBadSize", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to failed to decode image, see inner exception.

+        /// </summary>

+        internal static string AvatarFormatExceptionCantDecode {

+            get {

+                return ResourceManager.GetString("AvatarFormatExceptionCantDecode", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to unknown error.

+        /// </summary>

+        internal static string AvatarFormatExceptionUnknownError {

+            get {

+                return ResourceManager.GetString("AvatarFormatExceptionUnknownError", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to image&apos;s actual mime type is not the specified one.

+        /// </summary>

+        internal static string AvatarFormatExceptionUnmatchedFormat {

+            get {

+                return ResourceManager.GetString("AvatarFormatExceptionUnmatchedFormat", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The password is wrong..

+        /// </summary>

+        internal static string BadPasswordException {

+            get {

+                return ResourceManager.GetString("BadPasswordException", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The hashes password is of bad format. It might not be created by server..

+        /// </summary>

+        internal static string HashedPasswordBadFromatException {

+            get {

+                return ResourceManager.GetString("HashedPasswordBadFromatException", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Not of valid base64 format. See inner exception..

+        /// </summary>

+        internal static string HashedPasswordBadFromatExceptionNotBase64 {

+            get {

+                return ResourceManager.GetString("HashedPasswordBadFromatExceptionNotBase64", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Decoded hashed password is of length 0..

+        /// </summary>

+        internal static string HashedPasswordBadFromatExceptionNotLength0 {

+            get {

+                return ResourceManager.GetString("HashedPasswordBadFromatExceptionNotLength0", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to See inner exception..

+        /// </summary>

+        internal static string HashedPasswordBadFromatExceptionNotOthers {

+            get {

+                return ResourceManager.GetString("HashedPasswordBadFromatExceptionNotOthers", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Salt length &lt; 128 bits..

+        /// </summary>

+        internal static string HashedPasswordBadFromatExceptionNotSaltTooShort {

+            get {

+                return ResourceManager.GetString("HashedPasswordBadFromatExceptionNotSaltTooShort", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Subkey length &lt; 128 bits..

+        /// </summary>

+        internal static string HashedPasswordBadFromatExceptionNotSubkeyTooShort {

+            get {

+                return ResourceManager.GetString("HashedPasswordBadFromatExceptionNotSubkeyTooShort", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Unknown format marker..

+        /// </summary>

+        internal static string HashedPasswordBadFromatExceptionNotUnknownMarker {

+            get {

+                return ResourceManager.GetString("HashedPasswordBadFromatExceptionNotUnknownMarker", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The version of the jwt token is old..

+        /// </summary>

+        internal static string JwtBadVersionException {

+            get {

+                return ResourceManager.GetString("JwtBadVersionException", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The token didn&apos;t pass verification because {0}, see inner exception for information..

+        /// </summary>

+        internal static string JwtVerifyException {

+            get {

+                return ResourceManager.GetString("JwtVerifyException", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to token is expired..

+        /// </summary>

+        internal static string JwtVerifyExceptionExpired {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionExpired", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to id claim is not a number..

+        /// </summary>

+        internal static string JwtVerifyExceptionIdClaimBadFormat {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionIdClaimBadFormat", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to id claim does not exist..

+        /// </summary>

+        internal static string JwtVerifyExceptionNoIdClaim {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionNoIdClaim", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to version claim does not exist..

+        /// </summary>

+        internal static string JwtVerifyExceptionNoVersionClaim {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionNoVersionClaim", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to version of token is old..

+        /// </summary>

+        internal static string JwtVerifyExceptionOldVersion {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionOldVersion", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to uncommon error..

+        /// </summary>

+        internal static string JwtVerifyExceptionOthers {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionOthers", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to unknown error code..

+        /// </summary>

+        internal static string JwtVerifyExceptionUnknown {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionUnknown", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to version claim is not a number..

+        /// </summary>

+        internal static string JwtVerifyExceptionVersionClaimBadFormat {

+            get {

+                return ResourceManager.GetString("JwtVerifyExceptionVersionClaimBadFormat", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The username is of bad format..

+        /// </summary>

+        internal static string UsernameBadFormatException {

+            get {

+                return ResourceManager.GetString("UsernameBadFormatException", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The username already exists..

+        /// </summary>

+        internal static string UsernameConfictException {

+            get {

+                return ResourceManager.GetString("UsernameConfictException", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to The user does not exist..

+        /// </summary>

+        internal static string UserNotExistException {

+            get {

+                return ResourceManager.GetString("UserNotExistException", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Services/Exception.resx b/Timeline/Resources/Services/Exception.resx
new file mode 100644
index 00000000..12bf9afb
--- /dev/null
+++ b/Timeline/Resources/Services/Exception.resx
@@ -0,0 +1,198 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="AvatarFormatException" xml:space="preserve">

+    <value>Avartar is of bad format because {0}.</value>

+  </data>

+  <data name="AvatarFormatExceptionBadSize" xml:space="preserve">

+    <value>image is not a square, aka, width is not equal to height</value>

+  </data>

+  <data name="AvatarFormatExceptionCantDecode" xml:space="preserve">

+    <value>failed to decode image, see inner exception</value>

+  </data>

+  <data name="AvatarFormatExceptionUnknownError" xml:space="preserve">

+    <value>unknown error</value>

+  </data>

+  <data name="AvatarFormatExceptionUnmatchedFormat" xml:space="preserve">

+    <value>image's actual mime type is not the specified one</value>

+  </data>

+  <data name="BadPasswordException" xml:space="preserve">

+    <value>The password is wrong.</value>

+  </data>

+  <data name="HashedPasswordBadFromatException" xml:space="preserve">

+    <value>The hashes password is of bad format. It might not be created by server.</value>

+  </data>

+  <data name="HashedPasswordBadFromatExceptionNotBase64" xml:space="preserve">

+    <value>Not of valid base64 format. See inner exception.</value>

+  </data>

+  <data name="HashedPasswordBadFromatExceptionNotLength0" xml:space="preserve">

+    <value>Decoded hashed password is of length 0.</value>

+  </data>

+  <data name="HashedPasswordBadFromatExceptionNotOthers" xml:space="preserve">

+    <value>See inner exception.</value>

+  </data>

+  <data name="HashedPasswordBadFromatExceptionNotSaltTooShort" xml:space="preserve">

+    <value>Salt length &lt; 128 bits.</value>

+  </data>

+  <data name="HashedPasswordBadFromatExceptionNotSubkeyTooShort" xml:space="preserve">

+    <value>Subkey length &lt; 128 bits.</value>

+  </data>

+  <data name="HashedPasswordBadFromatExceptionNotUnknownMarker" xml:space="preserve">

+    <value>Unknown format marker.</value>

+  </data>

+  <data name="JwtBadVersionException" xml:space="preserve">

+    <value>The version of the jwt token is old.</value>

+  </data>

+  <data name="JwtVerifyException" xml:space="preserve">

+    <value>The token didn't pass verification because {0}, see inner exception for information.</value>

+  </data>

+  <data name="JwtVerifyExceptionExpired" xml:space="preserve">

+    <value>token is expired.</value>

+  </data>

+  <data name="JwtVerifyExceptionIdClaimBadFormat" xml:space="preserve">

+    <value>id claim is not a number.</value>

+  </data>

+  <data name="JwtVerifyExceptionNoIdClaim" xml:space="preserve">

+    <value>id claim does not exist.</value>

+  </data>

+  <data name="JwtVerifyExceptionNoVersionClaim" xml:space="preserve">

+    <value>version claim does not exist.</value>

+  </data>

+  <data name="JwtVerifyExceptionOldVersion" xml:space="preserve">

+    <value>version of token is old.</value>

+  </data>

+  <data name="JwtVerifyExceptionOthers" xml:space="preserve">

+    <value>uncommon error.</value>

+  </data>

+  <data name="JwtVerifyExceptionUnknown" xml:space="preserve">

+    <value>unknown error code.</value>

+  </data>

+  <data name="JwtVerifyExceptionVersionClaimBadFormat" xml:space="preserve">

+    <value>version claim is not a number.</value>

+  </data>

+  <data name="UsernameBadFormatException" xml:space="preserve">

+    <value>The username is of bad format.</value>

+  </data>

+  <data name="UsernameConfictException" xml:space="preserve">

+    <value>The username already exists.</value>

+  </data>

+  <data name="UserNotExistException" xml:space="preserve">

+    <value>The user does not exist.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Services/UserAvatarService.Designer.cs b/Timeline/Resources/Services/UserAvatarService.Designer.cs
new file mode 100644
index 00000000..6ee6fef9
--- /dev/null
+++ b/Timeline/Resources/Services/UserAvatarService.Designer.cs
@@ -0,0 +1,108 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Services {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class UserAvatarService {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal UserAvatarService() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Services.UserAvatarService", typeof(UserAvatarService).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Data of avatar is null..

+        /// </summary>

+        internal static string ArgumentAvatarDataNull {

+            get {

+                return ResourceManager.GetString("ArgumentAvatarDataNull", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Type of avatar is null or empty..

+        /// </summary>

+        internal static string ArgumentAvatarTypeNullOrEmpty {

+            get {

+                return ResourceManager.GetString("ArgumentAvatarTypeNullOrEmpty", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Database corupted! One of type and data of a avatar is null but the other is not..

+        /// </summary>

+        internal static string DatabaseCorruptedDataAndTypeNotSame {

+            get {

+                return ResourceManager.GetString("DatabaseCorruptedDataAndTypeNotSame", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Created an entry in user_avatars..

+        /// </summary>

+        internal static string LogCreateEntity {

+            get {

+                return ResourceManager.GetString("LogCreateEntity", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Updated an entry in user_avatars..

+        /// </summary>

+        internal static string LogUpdateEntity {

+            get {

+                return ResourceManager.GetString("LogUpdateEntity", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Services/UserAvatarService.resx b/Timeline/Resources/Services/UserAvatarService.resx
new file mode 100644
index 00000000..3269bf13
--- /dev/null
+++ b/Timeline/Resources/Services/UserAvatarService.resx
@@ -0,0 +1,135 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ArgumentAvatarDataNull" xml:space="preserve">

+    <value>Data of avatar is null.</value>

+  </data>

+  <data name="ArgumentAvatarTypeNullOrEmpty" xml:space="preserve">

+    <value>Type of avatar is null or empty.</value>

+  </data>

+  <data name="DatabaseCorruptedDataAndTypeNotSame" xml:space="preserve">

+    <value>Database corupted! One of type and data of a avatar is null but the other is not.</value>

+  </data>

+  <data name="LogCreateEntity" xml:space="preserve">

+    <value>Created an entry in user_avatars.</value>

+  </data>

+  <data name="LogUpdateEntity" xml:space="preserve">

+    <value>Updated an entry in user_avatars.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Resources/Services/UserService.Designer.cs b/Timeline/Resources/Services/UserService.Designer.cs
new file mode 100644
index 00000000..2a04dded
--- /dev/null
+++ b/Timeline/Resources/Services/UserService.Designer.cs
@@ -0,0 +1,126 @@
+//------------------------------------------------------------------------------

+// <auto-generated>

+//     This code was generated by a tool.

+//     Runtime Version:4.0.30319.42000

+//

+//     Changes to this file may cause incorrect behavior and will be lost if

+//     the code is regenerated.

+// </auto-generated>

+//------------------------------------------------------------------------------

+

+namespace Timeline.Resources.Services {

+    using System;

+    

+    

+    /// <summary>

+    ///   A strongly-typed resource class, for looking up localized strings, etc.

+    /// </summary>

+    // This class was auto-generated by the StronglyTypedResourceBuilder

+    // class via a tool like ResGen or Visual Studio.

+    // To add or remove a member, edit your .ResX file then rerun ResGen

+    // with the /str option, or rebuild your VS project.

+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "16.0.0.0")]

+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]

+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]

+    internal class UserService {

+        

+        private static global::System.Resources.ResourceManager resourceMan;

+        

+        private static global::System.Globalization.CultureInfo resourceCulture;

+        

+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]

+        internal UserService() {

+        }

+        

+        /// <summary>

+        ///   Returns the cached ResourceManager instance used by this class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Resources.ResourceManager ResourceManager {

+            get {

+                if (object.ReferenceEquals(resourceMan, null)) {

+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("Timeline.Resources.Services.UserService", typeof(UserService).Assembly);

+                    resourceMan = temp;

+                }

+                return resourceMan;

+            }

+        }

+        

+        /// <summary>

+        ///   Overrides the current thread's CurrentUICulture property for all

+        ///   resource lookups using this strongly typed resource class.

+        /// </summary>

+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]

+        internal static global::System.Globalization.CultureInfo Culture {

+            get {

+                return resourceCulture;

+            }

+            set {

+                resourceCulture = value;

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to New username is of bad format..

+        /// </summary>

+        internal static string ExceptionNewUsernameBadFormat {

+            get {

+                return ResourceManager.GetString("ExceptionNewUsernameBadFormat", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to Old username is of bad format..

+        /// </summary>

+        internal static string ExceptionOldUsernameBadFormat {

+            get {

+                return ResourceManager.GetString("ExceptionOldUsernameBadFormat", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A cache entry is created..

+        /// </summary>

+        internal static string LogCacheCreate {

+            get {

+                return ResourceManager.GetString("LogCacheCreate", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A cache entry is removed..

+        /// </summary>

+        internal static string LogCacheRemove {

+            get {

+                return ResourceManager.GetString("LogCacheRemove", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A new user entry is added to the database..

+        /// </summary>

+        internal static string LogDatabaseCreate {

+            get {

+                return ResourceManager.GetString("LogDatabaseCreate", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user entry is removed from the database..

+        /// </summary>

+        internal static string LogDatabaseRemove {

+            get {

+                return ResourceManager.GetString("LogDatabaseRemove", resourceCulture);

+            }

+        }

+        

+        /// <summary>

+        ///   Looks up a localized string similar to A user entry is updated to the database..

+        /// </summary>

+        internal static string LogDatabaseUpdate {

+            get {

+                return ResourceManager.GetString("LogDatabaseUpdate", resourceCulture);

+            }

+        }

+    }

+}

diff --git a/Timeline/Resources/Services/UserService.resx b/Timeline/Resources/Services/UserService.resx
new file mode 100644
index 00000000..3670d8f9
--- /dev/null
+++ b/Timeline/Resources/Services/UserService.resx
@@ -0,0 +1,141 @@
+<?xml version="1.0" encoding="utf-8"?>

+<root>

+  <!-- 

+    Microsoft ResX Schema 

+    

+    Version 2.0

+    

+    The primary goals of this format is to allow a simple XML format 

+    that is mostly human readable. The generation and parsing of the 

+    various data types are done through the TypeConverter classes 

+    associated with the data types.

+    

+    Example:

+    

+    ... ado.net/XML headers & schema ...

+    <resheader name="resmimetype">text/microsoft-resx</resheader>

+    <resheader name="version">2.0</resheader>

+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>

+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>

+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>

+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>

+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">

+        <value>[base64 mime encoded serialized .NET Framework object]</value>

+    </data>

+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">

+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>

+        <comment>This is a comment</comment>

+    </data>

+                

+    There are any number of "resheader" rows that contain simple 

+    name/value pairs.

+    

+    Each data row contains a name, and value. The row also contains a 

+    type or mimetype. Type corresponds to a .NET class that support 

+    text/value conversion through the TypeConverter architecture. 

+    Classes that don't support this are serialized and stored with the 

+    mimetype set.

+    

+    The mimetype is used for serialized objects, and tells the 

+    ResXResourceReader how to depersist the object. This is currently not 

+    extensible. For a given mimetype the value must be set accordingly:

+    

+    Note - application/x-microsoft.net.object.binary.base64 is the format 

+    that the ResXResourceWriter will generate, however the reader can 

+    read any of the formats listed below.

+    

+    mimetype: application/x-microsoft.net.object.binary.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter

+            : and then encoded with base64 encoding.

+    

+    mimetype: application/x-microsoft.net.object.soap.base64

+    value   : The object must be serialized with 

+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter

+            : and then encoded with base64 encoding.

+

+    mimetype: application/x-microsoft.net.object.bytearray.base64

+    value   : The object must be serialized into a byte array 

+            : using a System.ComponentModel.TypeConverter

+            : and then encoded with base64 encoding.

+    -->

+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">

+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />

+    <xsd:element name="root" msdata:IsDataSet="true">

+      <xsd:complexType>

+        <xsd:choice maxOccurs="unbounded">

+          <xsd:element name="metadata">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" />

+              </xsd:sequence>

+              <xsd:attribute name="name" use="required" type="xsd:string" />

+              <xsd:attribute name="type" type="xsd:string" />

+              <xsd:attribute name="mimetype" type="xsd:string" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="assembly">

+            <xsd:complexType>

+              <xsd:attribute name="alias" type="xsd:string" />

+              <xsd:attribute name="name" type="xsd:string" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="data">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />

+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />

+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />

+              <xsd:attribute ref="xml:space" />

+            </xsd:complexType>

+          </xsd:element>

+          <xsd:element name="resheader">

+            <xsd:complexType>

+              <xsd:sequence>

+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />

+              </xsd:sequence>

+              <xsd:attribute name="name" type="xsd:string" use="required" />

+            </xsd:complexType>

+          </xsd:element>

+        </xsd:choice>

+      </xsd:complexType>

+    </xsd:element>

+  </xsd:schema>

+  <resheader name="resmimetype">

+    <value>text/microsoft-resx</value>

+  </resheader>

+  <resheader name="version">

+    <value>2.0</value>

+  </resheader>

+  <resheader name="reader">

+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <resheader name="writer">

+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>

+  </resheader>

+  <data name="ExceptionNewUsernameBadFormat" xml:space="preserve">

+    <value>New username is of bad format.</value>

+  </data>

+  <data name="ExceptionOldUsernameBadFormat" xml:space="preserve">

+    <value>Old username is of bad format.</value>

+  </data>

+  <data name="LogCacheCreate" xml:space="preserve">

+    <value>A cache entry is created.</value>

+  </data>

+  <data name="LogCacheRemove" xml:space="preserve">

+    <value>A cache entry is removed.</value>

+  </data>

+  <data name="LogDatabaseCreate" xml:space="preserve">

+    <value>A new user entry is added to the database.</value>

+  </data>

+  <data name="LogDatabaseRemove" xml:space="preserve">

+    <value>A user entry is removed from the database.</value>

+  </data>

+  <data name="LogDatabaseUpdate" xml:space="preserve">

+    <value>A user entry is updated to the database.</value>

+  </data>

+</root>
\ No newline at end of file
diff --git a/Timeline/Services/AvatarFormatException.cs b/Timeline/Services/AvatarFormatException.cs
new file mode 100644
index 00000000..788eabb2
--- /dev/null
+++ b/Timeline/Services/AvatarFormatException.cs
@@ -0,0 +1,51 @@
+using System;

+using System.Globalization;

+

+namespace Timeline.Services

+{

+    /// <summary>

+    /// Thrown when avatar is of bad format.

+    /// </summary>

+    [Serializable]

+    public class AvatarFormatException : Exception

+    {

+        public enum ErrorReason

+        {

+            /// <summary>

+            /// Decoding image failed.

+            /// </summary>

+            CantDecode,

+            /// <summary>

+            /// Decoding succeeded but the real type is not the specified type.

+            /// </summary>

+            UnmatchedFormat,

+            /// <summary>

+            /// Image is not a square.

+            /// </summary>

+            BadSize

+        }

+

+        public AvatarFormatException() : base(MakeMessage(null)) { }

+        public AvatarFormatException(string message) : base(message) { }

+        public AvatarFormatException(string message, Exception inner) : base(message, inner) { }

+

+        public AvatarFormatException(Avatar avatar, ErrorReason error) : base(MakeMessage(error)) { Avatar = avatar; Error = error; }

+        public AvatarFormatException(Avatar avatar, ErrorReason error, Exception inner) : base(MakeMessage(error), inner) { Avatar = avatar; Error = error; }

+

+        protected AvatarFormatException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+

+        private static string MakeMessage(ErrorReason? reason) =>

+            string.Format(CultureInfo.InvariantCulture, Resources.Services.Exception.AvatarFormatException, reason switch

+            {

+                ErrorReason.CantDecode => Resources.Services.Exception.AvatarFormatExceptionCantDecode,

+                ErrorReason.UnmatchedFormat => Resources.Services.Exception.AvatarFormatExceptionUnmatchedFormat,

+                ErrorReason.BadSize => Resources.Services.Exception.AvatarFormatExceptionBadSize,

+                _ => Resources.Services.Exception.AvatarFormatExceptionUnknownError

+            });

+

+        public ErrorReason? Error { get; set; }

+        public Avatar? Avatar { get; set; }

+    }

+}

diff --git a/Timeline/Services/BadPasswordException.cs b/Timeline/Services/BadPasswordException.cs
new file mode 100644
index 00000000..ee8a42db
--- /dev/null
+++ b/Timeline/Services/BadPasswordException.cs
@@ -0,0 +1,27 @@
+using System;

+using Timeline.Helpers;

+

+namespace Timeline.Services

+{

+    [Serializable]

+    public class BadPasswordException : Exception

+    {

+        public BadPasswordException() : base(Resources.Services.Exception.UserNotExistException) { }

+        public BadPasswordException(string message, Exception inner) : base(message, inner) { }

+

+        public BadPasswordException(string badPassword)

+            : base(Log.Format(Resources.Services.Exception.UserNotExistException, ("Bad Password", badPassword)))

+        {

+            Password = badPassword;

+        }

+

+        protected BadPasswordException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+

+        /// <summary>

+        /// The wrong password.

+        /// </summary>

+        public string? Password { get; set; }

+    }

+}

diff --git a/Timeline/Services/DatabaseExtensions.cs b/Timeline/Services/DatabaseExtensions.cs
index a37cf05b..62b22f00 100644
--- a/Timeline/Services/DatabaseExtensions.cs
+++ b/Timeline/Services/DatabaseExtensions.cs
@@ -4,22 +4,27 @@ using System.Collections.Generic;
 using System.Linq;

 using System.Threading.Tasks;

 using Timeline.Entities;

+using Timeline.Models.Validation;

 

 namespace Timeline.Services

 {

-    public static class DatabaseExtensions

+    internal static class DatabaseExtensions

     {

         /// <summary>

         /// Check the existence and get the id of the user.

         /// </summary>

         /// <param name="username">The username of the user.</param>

         /// <returns>The user id.</returns>

-        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty.</exception>

+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="username"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown if <paramref name="username"/> is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown if user does not exist.</exception>

-        public static async Task<long> CheckAndGetUser(DbSet<User> userDbSet, string username)

+        internal static async Task<long> CheckAndGetUser(DbSet<User> userDbSet, UsernameValidator validator, string username)

         {

-            if (string.IsNullOrEmpty(username))

-                throw new ArgumentException("Username is null or empty.", nameof(username));

+            if (username == null)

+                throw new ArgumentNullException(nameof(username));

+            var (result, messageGenerator) = validator.Validate(username);

+            if (!result)

+                throw new UsernameBadFormatException(username, messageGenerator(null));

 

             var userId = await userDbSet.Where(u => u.Name == username).Select(u => u.Id).SingleOrDefaultAsync();

             if (userId == 0)

diff --git a/Timeline/Services/ETagGenerator.cs b/Timeline/Services/ETagGenerator.cs
index e2abebdc..d328ea20 100644
--- a/Timeline/Services/ETagGenerator.cs
+++ b/Timeline/Services/ETagGenerator.cs
@@ -1,33 +1,45 @@
 using System;

 using System.Security.Cryptography;

+using System.Threading.Tasks;

 

 namespace Timeline.Services

 {

     public interface IETagGenerator

     {

-        string Generate(byte[] source);

+        /// <summary>

+        /// Generate a etag for given source.

+        /// </summary>

+        /// <param name="source">The source data.</param>

+        /// <returns>The generated etag.</returns>

+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="source"/> is null.</exception>

+        Task<string> Generate(byte[] source);

     }

 

-    public class ETagGenerator : IETagGenerator, IDisposable

+    public sealed class ETagGenerator : IETagGenerator, IDisposable

     {

         private readonly SHA1 _sha1;

 

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Security", "CA5350:Do Not Use Weak Cryptographic Algorithms", Justification = "Sha1 is enough ??? I don't know.")]

         public ETagGenerator()

         {

             _sha1 = SHA1.Create();

         }

 

-        public string Generate(byte[] source)

+        public Task<string> Generate(byte[] source)

         {

-            if (source == null || source.Length == 0)

-                throw new ArgumentException("Source is null or empty.", nameof(source));

+            if (source == null)

+                throw new ArgumentNullException(nameof(source));

 

-            return Convert.ToBase64String(_sha1.ComputeHash(source));

+            return Task.Run(() => Convert.ToBase64String(_sha1.ComputeHash(source)));

         }

 

+        private bool _disposed = false; // To detect redundant calls

+

         public void Dispose()

         {

+            if (_disposed) return;

             _sha1.Dispose();

+            _disposed = true;

         }

     }

 }

diff --git a/Timeline/Services/JwtBadVersionException.cs b/Timeline/Services/JwtBadVersionException.cs
new file mode 100644
index 00000000..4ce17710
--- /dev/null
+++ b/Timeline/Services/JwtBadVersionException.cs
@@ -0,0 +1,36 @@
+using System;

+using Timeline.Helpers;

+

+namespace Timeline.Services

+{

+    [Serializable]

+    public class JwtBadVersionException : Exception

+    {

+        public JwtBadVersionException() : base(Resources.Services.Exception.JwtBadVersionException) { }

+        public JwtBadVersionException(string message) : base(message) { }

+        public JwtBadVersionException(string message, Exception inner) : base(message, inner) { }

+

+        public JwtBadVersionException(long tokenVersion, long requiredVersion)

+            : base(Log.Format(Resources.Services.Exception.JwtBadVersionException,

+                ("Token Version", tokenVersion),

+                ("Required Version", requiredVersion)))

+        {

+            TokenVersion = tokenVersion;

+            RequiredVersion = requiredVersion;

+        }

+

+        protected JwtBadVersionException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+

+        /// <summary>

+        /// The version in the token.

+        /// </summary>

+        public long? TokenVersion { get; set; }

+

+        /// <summary>

+        /// The version required.

+        /// </summary>

+        public long? RequiredVersion { get; set; }

+    }

+}

diff --git a/Timeline/Services/JwtService.cs b/Timeline/Services/JwtService.cs
index 350c5e80..bf92966a 100644
--- a/Timeline/Services/JwtService.cs
+++ b/Timeline/Services/JwtService.cs
@@ -1,6 +1,7 @@
 using Microsoft.Extensions.Options;

 using Microsoft.IdentityModel.Tokens;

 using System;

+using System.Globalization;

 using System.IdentityModel.Tokens.Jwt;

 using System.Security.Claims;

 using System.Text;

@@ -14,57 +15,6 @@ namespace Timeline.Services
         public long Version { get; set; }

     }

 

-    [Serializable]

-    public class JwtTokenVerifyException : Exception

-    {

-        public static class ErrorCodes

-        {

-            // Codes in -1000 ~ -1999 usually means the user provides a token that is not created by this server.

-

-            public const int Others = -1001;

-            public const int NoIdClaim = -1002;

-            public const int IdClaimBadFormat = -1003;

-            public const int NoVersionClaim = -1004;

-            public const int VersionClaimBadFormat = -1005;

-

-            /// <summary>

-            /// Corresponds to <see cref="SecurityTokenExpiredException"/>.

-            /// </summary>

-            public const int Expired = -2001;

-        }

-

-        public JwtTokenVerifyException(int code) : base(GetErrorMessage(code)) { ErrorCode = code; }

-        public JwtTokenVerifyException(string message, int code) : base(message) { ErrorCode = code; }

-        public JwtTokenVerifyException(Exception inner, int code) : base(GetErrorMessage(code), inner) { ErrorCode = code; }

-        public JwtTokenVerifyException(string message, Exception inner, int code) : base(message, inner) { ErrorCode = code; }

-        protected JwtTokenVerifyException(

-          System.Runtime.Serialization.SerializationInfo info,

-          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

-

-        public int ErrorCode { get; private set; }

-

-        private static string GetErrorMessage(int errorCode)

-        {

-            switch (errorCode)

-            {

-                case ErrorCodes.Others:

-                    return "Uncommon error, see inner exception for more information.";

-                case ErrorCodes.NoIdClaim:

-                    return "Id claim does not exist.";

-                case ErrorCodes.IdClaimBadFormat:

-                    return "Id claim is not a number.";

-                case ErrorCodes.NoVersionClaim:

-                    return "Version claim does not exist.";

-                case ErrorCodes.VersionClaimBadFormat:

-                    return "Version claim is not a number";

-                case ErrorCodes.Expired:

-                    return "Token is expired.";

-                default:

-                    return "Unknown error code.";

-            }

-        }

-    }

-

     public interface IJwtService

     {

         /// <summary>

@@ -83,7 +33,7 @@ namespace Timeline.Services
         /// <param name="token">The token string to verify.</param>

         /// <returns>Return the saved info in token.</returns>

         /// <exception cref="ArgumentNullException">Thrown when <paramref name="token"/> is null.</exception>

-        /// <exception cref="JwtTokenVerifyException">Thrown when the token is invalid.</exception>

+        /// <exception cref="JwtVerifyException">Thrown when the token is invalid.</exception>

         TokenInfo VerifyJwtToken(string token);

 

     }

@@ -110,8 +60,8 @@ namespace Timeline.Services
             var config = _jwtConfig.CurrentValue;

 

             var identity = new ClaimsIdentity();

-            identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, tokenInfo.Id.ToString(), ClaimValueTypes.Integer64));

-            identity.AddClaim(new Claim(VersionClaimType, tokenInfo.Version.ToString(), ClaimValueTypes.Integer64));

+            identity.AddClaim(new Claim(ClaimTypes.NameIdentifier, tokenInfo.Id.ToString(CultureInfo.InvariantCulture.NumberFormat), ClaimValueTypes.Integer64));

+            identity.AddClaim(new Claim(VersionClaimType, tokenInfo.Version.ToString(CultureInfo.InvariantCulture.NumberFormat), ClaimValueTypes.Integer64));

 

             var tokenDescriptor = new SecurityTokenDescriptor()

             {

@@ -153,15 +103,15 @@ namespace Timeline.Services
 

                 var idClaim = principal.FindFirstValue(ClaimTypes.NameIdentifier);

                 if (idClaim == null)

-                    throw new JwtTokenVerifyException(JwtTokenVerifyException.ErrorCodes.NoIdClaim);

+                    throw new JwtVerifyException(JwtVerifyException.ErrorCodes.NoIdClaim);

                 if (!long.TryParse(idClaim, out var id))

-                    throw new JwtTokenVerifyException(JwtTokenVerifyException.ErrorCodes.IdClaimBadFormat);

+                    throw new JwtVerifyException(JwtVerifyException.ErrorCodes.IdClaimBadFormat);

 

                 var versionClaim = principal.FindFirstValue(VersionClaimType);

                 if (versionClaim == null)

-                    throw new JwtTokenVerifyException(JwtTokenVerifyException.ErrorCodes.NoVersionClaim);

+                    throw new JwtVerifyException(JwtVerifyException.ErrorCodes.NoVersionClaim);

                 if (!long.TryParse(versionClaim, out var version))

-                    throw new JwtTokenVerifyException(JwtTokenVerifyException.ErrorCodes.VersionClaimBadFormat);

+                    throw new JwtVerifyException(JwtVerifyException.ErrorCodes.VersionClaimBadFormat);

 

                 return new TokenInfo

                 {

@@ -171,11 +121,11 @@ namespace Timeline.Services
             }

             catch (SecurityTokenExpiredException e)

             {

-                throw new JwtTokenVerifyException(e, JwtTokenVerifyException.ErrorCodes.Expired);

+                throw new JwtVerifyException(e, JwtVerifyException.ErrorCodes.Expired);

             }

             catch (Exception e)

             {

-                throw new JwtTokenVerifyException(e, JwtTokenVerifyException.ErrorCodes.Others);

+                throw new JwtVerifyException(e, JwtVerifyException.ErrorCodes.Others);

             }

         }

     }

diff --git a/Timeline/Services/JwtVerifyException.cs b/Timeline/Services/JwtVerifyException.cs
new file mode 100644
index 00000000..a915b51a
--- /dev/null
+++ b/Timeline/Services/JwtVerifyException.cs
@@ -0,0 +1,59 @@
+using Microsoft.IdentityModel.Tokens;

+using System;

+using System.Globalization;

+using static Timeline.Resources.Services.Exception;

+

+namespace Timeline.Services

+{

+    [Serializable]

+    public class JwtVerifyException : Exception

+    {

+        public static class ErrorCodes

+        {

+            // Codes in -1000 ~ -1999 usually means the user provides a token that is not created by this server.

+

+            public const int Others = -1001;

+            public const int NoIdClaim = -1002;

+            public const int IdClaimBadFormat = -1003;

+            public const int NoVersionClaim = -1004;

+            public const int VersionClaimBadFormat = -1005;

+

+            /// <summary>

+            /// Corresponds to <see cref="SecurityTokenExpiredException"/>.

+            /// </summary>

+            public const int Expired = -2001;

+            public const int OldVersion = -2002;

+        }

+

+        public JwtVerifyException() : base(GetErrorMessage(0)) { }

+        public JwtVerifyException(string message) : base(message) { }

+        public JwtVerifyException(string message, Exception inner) : base(message, inner) { }

+

+        public JwtVerifyException(int code) : base(GetErrorMessage(code)) { ErrorCode = code; }

+        public JwtVerifyException(string message, int code) : base(message) { ErrorCode = code; }

+        public JwtVerifyException(Exception inner, int code) : base(GetErrorMessage(code), inner) { ErrorCode = code; }

+        public JwtVerifyException(string message, Exception inner, int code) : base(message, inner) { ErrorCode = code; }

+        protected JwtVerifyException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+

+        public int ErrorCode { get; set; }

+

+        private static string GetErrorMessage(int errorCode)

+        {

+            var reason = errorCode switch

+            {

+                ErrorCodes.Others => JwtVerifyExceptionOthers,

+                ErrorCodes.NoIdClaim => JwtVerifyExceptionNoIdClaim,

+                ErrorCodes.IdClaimBadFormat => JwtVerifyExceptionIdClaimBadFormat,

+                ErrorCodes.NoVersionClaim => JwtVerifyExceptionNoVersionClaim,

+                ErrorCodes.VersionClaimBadFormat => JwtVerifyExceptionVersionClaimBadFormat,

+                ErrorCodes.Expired => JwtVerifyExceptionExpired,

+                ErrorCodes.OldVersion => JwtVerifyExceptionOldVersion,

+                _ => JwtVerifyExceptionUnknown

+            };

+

+            return string.Format(CultureInfo.InvariantCulture, Resources.Services.Exception.JwtVerifyException, reason);

+        }

+    }

+}

diff --git a/Timeline/Services/PasswordService.cs b/Timeline/Services/PasswordService.cs
index e09a1365..e04a861b 100644
--- a/Timeline/Services/PasswordService.cs
+++ b/Timeline/Services/PasswordService.cs
@@ -12,13 +12,23 @@ namespace Timeline.Services
     [Serializable]

     public class HashedPasswordBadFromatException : Exception

     {

-        public HashedPasswordBadFromatException(string hashedPassword, string message) : base(message) { HashedPassword = hashedPassword; }

-        public HashedPasswordBadFromatException(string hashedPassword, string message, Exception inner) : base(message, inner) { HashedPassword = hashedPassword; }

+        private static string MakeMessage(string reason)

+        {

+            return Resources.Services.Exception.HashedPasswordBadFromatException + " Reason: " + reason;

+        }

+

+        public HashedPasswordBadFromatException() : base(Resources.Services.Exception.HashedPasswordBadFromatException) { }

+

+        public HashedPasswordBadFromatException(string message) : base(message) { }

+        public HashedPasswordBadFromatException(string message, Exception inner) : base(message, inner) { }

+

+        public HashedPasswordBadFromatException(string hashedPassword, string reason) : base(MakeMessage(reason)) { HashedPassword = hashedPassword; }

+        public HashedPasswordBadFromatException(string hashedPassword, string reason, Exception inner) : base(MakeMessage(reason), inner) { HashedPassword = hashedPassword; }

         protected HashedPasswordBadFromatException(

           System.Runtime.Serialization.SerializationInfo info,

           System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

 

-        public string HashedPassword { get; private set; }

+        public string? HashedPassword { get; set; }

     }

 

     public interface IPasswordService

@@ -140,22 +150,20 @@ namespace Timeline.Services
             }

             catch (FormatException e)

             {

-                throw new HashedPasswordBadFromatException(hashedPassword, "Not of valid base64 format. See inner exception.", e);

+                throw new HashedPasswordBadFromatException(hashedPassword, Resources.Services.Exception.HashedPasswordBadFromatExceptionNotBase64, e);

             }

 

             // read the format marker from the hashed password

             if (decodedHashedPassword.Length == 0)

             {

-                throw new HashedPasswordBadFromatException(hashedPassword, "Decoded hashed password is of length 0.");

+                throw new HashedPasswordBadFromatException(hashedPassword, Resources.Services.Exception.HashedPasswordBadFromatExceptionNotLength0);

             }

-            switch (decodedHashedPassword[0])

-            {

-                case 0x01:

-                    return VerifyHashedPasswordV3(decodedHashedPassword, providedPassword, hashedPassword);

 

-                default:

-                    throw new HashedPasswordBadFromatException(hashedPassword, "Unknown format marker.");

-            }

+            return (decodedHashedPassword[0]) switch

+            {

+                0x01 => VerifyHashedPasswordV3(decodedHashedPassword, providedPassword, hashedPassword),

+                _ => throw new HashedPasswordBadFromatException(hashedPassword, Resources.Services.Exception.HashedPasswordBadFromatExceptionNotUnknownMarker),

+            };

         }

 

         private bool VerifyHashedPasswordV3(byte[] hashedPassword, string password, string hashedPasswordString)

@@ -170,7 +178,7 @@ namespace Timeline.Services
                 // Read the salt: must be >= 128 bits

                 if (saltLength < 128 / 8)

                 {

-                    throw new HashedPasswordBadFromatException(hashedPasswordString, "Salt length < 128 bits.");

+                    throw new HashedPasswordBadFromatException(hashedPasswordString, Resources.Services.Exception.HashedPasswordBadFromatExceptionNotSaltTooShort);

                 }

                 byte[] salt = new byte[saltLength];

                 Buffer.BlockCopy(hashedPassword, 13, salt, 0, salt.Length);

@@ -179,7 +187,7 @@ namespace Timeline.Services
                 int subkeyLength = hashedPassword.Length - 13 - salt.Length;

                 if (subkeyLength < 128 / 8)

                 {

-                    throw new HashedPasswordBadFromatException(hashedPasswordString, "Subkey length < 128 bits.");

+                    throw new HashedPasswordBadFromatException(hashedPasswordString, Resources.Services.Exception.HashedPasswordBadFromatExceptionNotSubkeyTooShort);

                 }

                 byte[] expectedSubkey = new byte[subkeyLength];

                 Buffer.BlockCopy(hashedPassword, 13 + salt.Length, expectedSubkey, 0, expectedSubkey.Length);

@@ -193,7 +201,7 @@ namespace Timeline.Services
                 // This should never occur except in the case of a malformed payload, where

                 // we might go off the end of the array. Regardless, a malformed payload

                 // implies verification failed.

-                throw new HashedPasswordBadFromatException(hashedPasswordString, "See inner exception.", e);

+                throw new HashedPasswordBadFromatException(hashedPasswordString, Resources.Services.Exception.HashedPasswordBadFromatExceptionNotOthers, e);

             }

         }

 

diff --git a/Timeline/Services/UserAvatarService.cs b/Timeline/Services/UserAvatarService.cs
index ecec5a31..ff80003c 100644
--- a/Timeline/Services/UserAvatarService.cs
+++ b/Timeline/Services/UserAvatarService.cs
@@ -10,54 +10,25 @@ using System.IO;
 using System.Linq;

 using System.Threading.Tasks;

 using Timeline.Entities;

+using Timeline.Helpers;

+using Timeline.Models.Validation;

 

 namespace Timeline.Services

 {

     public class Avatar

     {

-        public string Type { get; set; }

-        public byte[] Data { get; set; }

+        public string Type { get; set; } = default!;

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Performance", "CA1819:Properties should not return arrays", Justification = "DTO Object")]

+        public byte[] Data { get; set; } = default!;

     }

 

     public class AvatarInfo

     {

-        public Avatar Avatar { get; set; }

+        public Avatar Avatar { get; set; } = default!;

         public DateTime LastModified { get; set; }

     }

 

     /// <summary>

-    /// Thrown when avatar is of bad format.

-    /// </summary>

-    [Serializable]

-    public class AvatarDataException : Exception

-    {

-        public enum ErrorReason

-        {

-            /// <summary>

-            /// Decoding image failed.

-            /// </summary>

-            CantDecode,

-            /// <summary>

-            /// Decoding succeeded but the real type is not the specified type.

-            /// </summary>

-            UnmatchedFormat,

-            /// <summary>

-            /// Image is not a square.

-            /// </summary>

-            BadSize

-        }

-

-        public AvatarDataException(Avatar avatar, ErrorReason error, string message) : base(message) { Avatar = avatar; Error = error; }

-        public AvatarDataException(Avatar avatar, ErrorReason error, string message, Exception inner) : base(message, inner) { Avatar = avatar; Error = error; }

-        protected AvatarDataException(

-          System.Runtime.Serialization.SerializationInfo info,

-          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

-

-        public ErrorReason Error { get; set; }

-        public Avatar Avatar { get; set; }

-    }

-

-    /// <summary>

     /// Provider for default user avatar.

     /// </summary>

     /// <remarks>

@@ -83,7 +54,7 @@ namespace Timeline.Services
         /// Validate a avatar's format and size info.

         /// </summary>

         /// <param name="avatar">The avatar to validate.</param>

-        /// <exception cref="AvatarDataException">Thrown when validation failed.</exception>

+        /// <exception cref="AvatarFormatException">Thrown when validation failed.</exception>

         Task Validate(Avatar avatar);

     }

 

@@ -94,16 +65,18 @@ namespace Timeline.Services
         /// </summary>

         /// <param name="username">The username of the user to get avatar etag of.</param>

         /// <returns>The etag.</returns>

-        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty.</exception>

+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="username"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown if the <paramref name="username"/> is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown if the user does not exist.</exception>

         Task<string> GetAvatarETag(string username);

 

         /// <summary>

-        /// Get avatar of a user. If the user has no avatar, a default one is returned.

+        /// Get avatar of a user. If the user has no avatar set, a default one is returned.

         /// </summary>

         /// <param name="username">The username of the user to get avatar of.</param>

         /// <returns>The avatar info.</returns>

-        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty.</exception>

+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="username"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown if the <paramref name="username"/> is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown if the user does not exist.</exception>

         Task<AvatarInfo> GetAvatar(string username);

 

@@ -112,38 +85,41 @@ namespace Timeline.Services
         /// </summary>

         /// <param name="username">The username of the user to set avatar for.</param>

         /// <param name="avatar">The avatar. Can be null to delete the saved avatar.</param>

-        /// <exception cref="ArgumentException">Throw if <paramref name="username"/> is null or empty.

-        /// Or thrown if <paramref name="avatar"/> is not null but <see cref="Avatar.Type"/> is null or empty or <see cref="Avatar.Data"/> is null.</exception>

+        /// <exception cref="ArgumentNullException">Throw if <paramref name="username"/> is null.</exception>

+        /// <exception cref="ArgumentException">Thrown if any field in <paramref name="avatar"/> is null when <paramref name="avatar"/> is not null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown if the <paramref name="username"/> is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown if the user does not exist.</exception>

-        /// <exception cref="AvatarDataException">Thrown if avatar is of bad format.</exception>

-        Task SetAvatar(string username, Avatar avatar);

+        /// <exception cref="AvatarFormatException">Thrown if avatar is of bad format.</exception>

+        Task SetAvatar(string username, Avatar? avatar);

     }

 

+    // TODO! : Make this configurable.

     public class DefaultUserAvatarProvider : IDefaultUserAvatarProvider

     {

-        private readonly IWebHostEnvironment _environment;

-

         private readonly IETagGenerator _eTagGenerator;

 

-        private byte[] _cacheData;

+        private readonly string _avatarPath;

+

+        private byte[] _cacheData = default!;

         private DateTime _cacheLastModified;

-        private string _cacheETag;

+        private string _cacheETag = default!;

 

+        [System.Diagnostics.CodeAnalysis.SuppressMessage("Design", "CA1062:Validate arguments of public methods", Justification = "DI.")]

         public DefaultUserAvatarProvider(IWebHostEnvironment environment, IETagGenerator eTagGenerator)

         {

-            _environment = environment;

+            _avatarPath = Path.Combine(environment.ContentRootPath, "default-avatar.png");

             _eTagGenerator = eTagGenerator;

         }

 

         private async Task CheckAndInit()

         {

-            if (_cacheData != null)

-                return;

-

-            var path = Path.Combine(_environment.ContentRootPath, "default-avatar.png");

-            _cacheData = await File.ReadAllBytesAsync(path);

-            _cacheLastModified = File.GetLastWriteTime(path);

-            _cacheETag = _eTagGenerator.Generate(_cacheData);

+            var path = _avatarPath;

+            if (_cacheData == null || File.GetLastWriteTime(path) > _cacheLastModified)

+            {

+                _cacheData = await File.ReadAllBytesAsync(path);

+                _cacheLastModified = File.GetLastWriteTime(path);

+                _cacheETag = await _eTagGenerator.Generate(_cacheData);

+            }

         }

 

         public async Task<string> GetDefaultAvatarETag()

@@ -175,17 +151,15 @@ namespace Timeline.Services
             {

                 try

                 {

-                    using (var image = Image.Load(avatar.Data, out IImageFormat format))

-                    {

-                        if (!format.MimeTypes.Contains(avatar.Type))

-                            throw new AvatarDataException(avatar, AvatarDataException.ErrorReason.UnmatchedFormat, "Image's actual mime type is not the specified one.");

-                        if (image.Width != image.Height)

-                            throw new AvatarDataException(avatar, AvatarDataException.ErrorReason.BadSize, "Image is not a square, aka, width is not equal to height.");

-                    }

+                    using var image = Image.Load(avatar.Data, out IImageFormat format);

+                    if (!format.MimeTypes.Contains(avatar.Type))

+                        throw new AvatarFormatException(avatar, AvatarFormatException.ErrorReason.UnmatchedFormat);

+                    if (image.Width != image.Height)

+                        throw new AvatarFormatException(avatar, AvatarFormatException.ErrorReason.BadSize);

                 }

                 catch (UnknownImageFormatException e)

                 {

-                    throw new AvatarDataException(avatar, AvatarDataException.ErrorReason.CantDecode, "Failed to decode image. See inner exception.", e);

+                    throw new AvatarFormatException(avatar, AvatarFormatException.ErrorReason.CantDecode, e);

                 }

             });

         }

@@ -203,25 +177,32 @@ namespace Timeline.Services
 

         private readonly IETagGenerator _eTagGenerator;

 

+        private readonly UsernameValidator _usernameValidator;

+

+        private readonly IClock _clock;

+

         public UserAvatarService(

             ILogger<UserAvatarService> logger,

             DatabaseContext database,

             IDefaultUserAvatarProvider defaultUserAvatarProvider,

             IUserAvatarValidator avatarValidator,

-            IETagGenerator eTagGenerator)

+            IETagGenerator eTagGenerator,

+            IClock clock)

         {

             _logger = logger;

             _database = database;

             _defaultUserAvatarProvider = defaultUserAvatarProvider;

             _avatarValidator = avatarValidator;

             _eTagGenerator = eTagGenerator;

+            _usernameValidator = new UsernameValidator();

+            _clock = clock;

         }

 

         public async Task<string> GetAvatarETag(string username)

         {

-            var userId = await DatabaseExtensions.CheckAndGetUser(_database.Users, username);

+            var userId = await DatabaseExtensions.CheckAndGetUser(_database.Users, _usernameValidator, username);

 

-            var eTag = (await _database.UserAvatars.Where(a => a.UserId == userId).Select(a => new { a.ETag }).SingleAsync()).ETag;

+            var eTag = (await _database.UserAvatars.Where(a => a.UserId == userId).Select(a => new { a.ETag }).SingleOrDefaultAsync())?.ETag;

             if (eTag == null)

                 return await _defaultUserAvatarProvider.GetDefaultAvatarETag();

             else

@@ -230,73 +211,88 @@ namespace Timeline.Services
 

         public async Task<AvatarInfo> GetAvatar(string username)

         {

-            var userId = await DatabaseExtensions.CheckAndGetUser(_database.Users, username);

+            var userId = await DatabaseExtensions.CheckAndGetUser(_database.Users, _usernameValidator, username);

 

-            var avatar = await _database.UserAvatars.Where(a => a.UserId == userId).Select(a => new { a.Type, a.Data, a.LastModified }).SingleAsync();

+            var avatarEntity = await _database.UserAvatars.Where(a => a.UserId == userId).Select(a => new { a.Type, a.Data, a.LastModified }).SingleOrDefaultAsync();

 

-            if ((avatar.Type == null) != (avatar.Data == null))

+            if (avatarEntity != null)

             {

-                _logger.LogCritical("Database corupted! One of type and data of a avatar is null but the other is not.");

-                throw new DatabaseCorruptedException();

-            }

+                if (!LanguageHelper.AreSame(avatarEntity.Data == null, avatarEntity.Type == null))

+                {

+                    var message = Resources.Services.UserAvatarService.DatabaseCorruptedDataAndTypeNotSame;

+                    _logger.LogCritical(message);

+                    throw new DatabaseCorruptedException(message);

+                }

 

-            if (avatar.Data == null)

-            {

-                var defaultAvatar = await _defaultUserAvatarProvider.GetDefaultAvatar();

-                defaultAvatar.LastModified = defaultAvatar.LastModified > avatar.LastModified ? defaultAvatar.LastModified : avatar.LastModified;

-                return defaultAvatar;

-            }

-            else

-            {

-                return new AvatarInfo

+                if (avatarEntity.Data != null)

                 {

-                    Avatar = new Avatar

+                    return new AvatarInfo

                     {

-                        Type = avatar.Type,

-                        Data = avatar.Data

-                    },

-                    LastModified = avatar.LastModified

-                };

+                        Avatar = new Avatar

+                        {

+                            Type = avatarEntity.Type!,

+                            Data = avatarEntity.Data

+                        },

+                        LastModified = avatarEntity.LastModified

+                    };

+                }

             }

+            var defaultAvatar = await _defaultUserAvatarProvider.GetDefaultAvatar();

+            if (avatarEntity != null)

+                defaultAvatar.LastModified = defaultAvatar.LastModified > avatarEntity.LastModified ? defaultAvatar.LastModified : avatarEntity.LastModified;

+            return defaultAvatar;

         }

 

-        public async Task SetAvatar(string username, Avatar avatar)

+        public async Task SetAvatar(string username, Avatar? avatar)

         {

             if (avatar != null)

             {

-                if (string.IsNullOrEmpty(avatar.Type))

-                    throw new ArgumentException("Type of avatar is null or empty.", nameof(avatar));

                 if (avatar.Data == null)

-                    throw new ArgumentException("Data of avatar is null.", nameof(avatar));

+                    throw new ArgumentException(Resources.Services.UserAvatarService.ArgumentAvatarDataNull, nameof(avatar));

+                if (string.IsNullOrEmpty(avatar.Type))

+                    throw new ArgumentException(Resources.Services.UserAvatarService.ArgumentAvatarTypeNullOrEmpty, nameof(avatar));

             }

 

-            var userId = await DatabaseExtensions.CheckAndGetUser(_database.Users, username);

-

-            var avatarEntity = await _database.UserAvatars.Where(a => a.UserId == userId).SingleAsync();

+            var userId = await DatabaseExtensions.CheckAndGetUser(_database.Users, _usernameValidator, username);

+            var avatarEntity = await _database.UserAvatars.Where(a => a.UserId == userId).SingleOrDefaultAsync();

 

             if (avatar == null)

             {

-                if (avatarEntity.Data == null)

+                if (avatarEntity == null || avatarEntity.Data == null)

+                {

                     return;

+                }

                 else

                 {

                     avatarEntity.Data = null;

                     avatarEntity.Type = null;

                     avatarEntity.ETag = null;

-                    avatarEntity.LastModified = DateTime.Now;

+                    avatarEntity.LastModified = _clock.GetCurrentTime();

                     await _database.SaveChangesAsync();

-                    _logger.LogInformation("Updated an entry in user_avatars.");

+                    _logger.LogInformation(Resources.Services.UserAvatarService.LogUpdateEntity);

                 }

             }

             else

             {

                 await _avatarValidator.Validate(avatar);

-                avatarEntity.Type = avatar.Type;

+                var create = avatarEntity == null;

+                if (create)

+                {

+                    avatarEntity = new UserAvatar();

+                }

+                avatarEntity!.Type = avatar.Type;

                 avatarEntity.Data = avatar.Data;

-                avatarEntity.ETag = _eTagGenerator.Generate(avatar.Data);

-                avatarEntity.LastModified = DateTime.Now;

+                avatarEntity.ETag = await _eTagGenerator.Generate(avatar.Data);

+                avatarEntity.LastModified = _clock.GetCurrentTime();

+                avatarEntity.UserId = userId;

+                if (create)

+                {

+                    _database.UserAvatars.Add(avatarEntity);

+                }

                 await _database.SaveChangesAsync();

-                _logger.LogInformation("Updated an entry in user_avatars.");

+                _logger.LogInformation(create ?

+                    Resources.Services.UserAvatarService.LogCreateEntity

+                    : Resources.Services.UserAvatarService.LogUpdateEntity);

             }

         }

     }

@@ -308,7 +304,7 @@ namespace Timeline.Services
             services.TryAddTransient<IETagGenerator, ETagGenerator>();

             services.AddScoped<IUserAvatarService, UserAvatarService>();

             services.AddSingleton<IDefaultUserAvatarProvider, DefaultUserAvatarProvider>();

-            services.AddSingleton<IUserAvatarValidator, UserAvatarValidator>();

+            services.AddTransient<IUserAvatarValidator, UserAvatarValidator>();

         }

     }

 }

diff --git a/Timeline/Services/UserDetailService.cs b/Timeline/Services/UserDetailService.cs
deleted file mode 100644
index 5e049435..00000000
--- a/Timeline/Services/UserDetailService.cs
+++ /dev/null
@@ -1,135 +0,0 @@
-using Microsoft.EntityFrameworkCore;

-using Microsoft.Extensions.DependencyInjection;

-using Microsoft.Extensions.Logging;

-using System;

-using System.Linq;

-using System.Threading.Tasks;

-using Timeline.Entities;

-using Timeline.Models;

-

-namespace Timeline.Services

-{

-    public interface IUserDetailService

-    {

-        /// <summary>

-        /// Get the nickname of user.

-        /// </summary>

-        /// <param name="username">The username to get nickname of.</param>

-        /// <returns>The user's nickname. Null if not set.</returns>

-        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty.</exception>

-        /// <exception cref="UserNotExistException">Thrown if user doesn't exist.</exception>

-        Task<string> GetUserNickname(string username);

-

-        /// <summary>

-        /// Get the detail of user.

-        /// </summary>

-        /// <param name="username">The username to get user detail of.</param>

-        /// <returns>The user detail.</returns>

-        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty.</exception>

-        /// <exception cref="UserNotExistException">Thrown if user doesn't exist.</exception>

-        Task<UserDetail> GetUserDetail(string username);

-

-        /// <summary>

-        /// Update the detail of user. This function does not do data check.

-        /// </summary>

-        /// <param name="username">The username to get user detail of.</param>

-        /// <param name="detail">The detail to update. Can't be null. Any null member means not set.</param>

-        /// <exception cref="ArgumentException">Thrown if <paramref name="username"/> is null or empty or <paramref name="detail"/> is null.</exception>

-        /// <exception cref="UserNotExistException">Thrown if user doesn't exist.</exception>

-        Task UpdateUserDetail(string username, UserDetail detail);

-    }

-

-    public class UserDetailService : IUserDetailService

-    {

-        private readonly ILogger<UserDetailService> _logger;

-

-        private readonly DatabaseContext _databaseContext;

-

-        public UserDetailService(ILogger<UserDetailService> logger, DatabaseContext databaseContext)

-        {

-            _logger = logger;

-            _databaseContext = databaseContext;

-        }

-

-        private async Task<UserDetailEntity> CreateEntity(long userId)

-        {

-            var entity = new UserDetailEntity()

-            {

-                UserId = userId

-            };

-            _databaseContext.UserDetails.Add(entity);

-            await _databaseContext.SaveChangesAsync();

-            _logger.LogInformation("An entity is created in user_details.");

-            return entity;

-        }

-

-        // Check the existence of user detail entry

-        private async Task<UserDetailEntity> CheckAndInit(long userId)

-        {

-            var detail = await _databaseContext.UserDetails.Where(e => e.UserId == userId).SingleOrDefaultAsync();

-            if (detail == null)

-            {

-                detail = await CreateEntity(userId);

-            }

-            return detail;

-        }

-

-        public async Task<string> GetUserNickname(string username)

-        {

-            var userId = await DatabaseExtensions.CheckAndGetUser(_databaseContext.Users, username);

-            var detail = await _databaseContext.UserDetails.Where(e => e.UserId == userId).Select(e => new { e.Nickname }).SingleOrDefaultAsync();

-            if (detail == null)

-            {

-                var entity = await CreateEntity(userId);

-                return null;

-            }

-            else

-            {

-                var nickname = detail.Nickname;

-                return string.IsNullOrEmpty(nickname) ? null : nickname;

-            }

-        }

-

-        public async Task<UserDetail> GetUserDetail(string username)

-        {

-            var userId = await DatabaseExtensions.CheckAndGetUser(_databaseContext.Users, username);

-            var detailEntity = await CheckAndInit(userId);

-            return UserDetail.From(detailEntity);

-        }

-

-        public async Task UpdateUserDetail(string username, UserDetail detail)

-        {

-            if (detail == null)

-                throw new ArgumentNullException(nameof(detail));

-

-            var userId = await DatabaseExtensions.CheckAndGetUser(_databaseContext.Users, username);

-            var detailEntity = await CheckAndInit(userId);

-

-            if (detail.Nickname != null)

-                detailEntity.Nickname = detail.Nickname;

-

-            if (detail.QQ != null)

-                detailEntity.QQ = detail.QQ;

-

-            if (detail.Email != null)

-                detailEntity.Email = detail.Email;

-

-            if (detail.PhoneNumber != null)

-                detailEntity.PhoneNumber = detail.PhoneNumber;

-

-            if (detail.Description != null)

-                detailEntity.Description = detail.Description;

-

-            await _databaseContext.SaveChangesAsync();

-            _logger.LogInformation("An entity is updated in user_details.");

-        }

-    }

-

-    public static class UserDetailServiceCollectionExtensions

-    {

-        public static void AddUserDetailService(this IServiceCollection services)

-        {

-            services.AddScoped<IUserDetailService, UserDetailService>();

-        }

-    }

-}

diff --git a/Timeline/Services/UserNotExistException.cs b/Timeline/Services/UserNotExistException.cs
new file mode 100644
index 00000000..c7317f56
--- /dev/null
+++ b/Timeline/Services/UserNotExistException.cs
@@ -0,0 +1,41 @@
+using System;

+using Timeline.Helpers;

+

+namespace Timeline.Services

+{

+    /// <summary>

+    /// The user requested does not exist.

+    /// </summary>

+    [Serializable]

+    public class UserNotExistException : Exception

+    {

+        public UserNotExistException() : base(Resources.Services.Exception.UserNotExistException) { }

+        public UserNotExistException(string message, Exception inner) : base(message, inner) { }

+

+        public UserNotExistException(string username)

+            : base(Log.Format(Resources.Services.Exception.UserNotExistException, ("Username", username)))

+        {

+            Username = username;

+        }

+

+        public UserNotExistException(long id)

+            : base(Log.Format(Resources.Services.Exception.UserNotExistException, ("Id", id)))

+        {

+            Id = id;

+        }

+

+        protected UserNotExistException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+

+        /// <summary>

+        /// The username of the user that does not exist.

+        /// </summary>

+        public string? Username { get; set; }

+

+        /// <summary>

+        /// The id of the user that does not exist.

+        /// </summary>

+        public long? Id { get; set; }

+    }

+}

diff --git a/Timeline/Services/UserService.cs b/Timeline/Services/UserService.cs
index 347b8cbb..8f354fc7 100644
--- a/Timeline/Services/UserService.cs
+++ b/Timeline/Services/UserService.cs
@@ -5,140 +5,16 @@ using System;
 using System.Linq;

 using System.Threading.Tasks;

 using Timeline.Entities;

+using Timeline.Helpers;

 using Timeline.Models;

 using Timeline.Models.Validation;

-using static Timeline.Helpers.MyLogHelper;

-using static Timeline.Models.UserUtility;

 

 namespace Timeline.Services

 {

     public class CreateTokenResult

     {

-        public string Token { get; set; }

-        public UserInfo User { get; set; }

-    }

-

-    [Serializable]

-    public class UserNotExistException : Exception

-    {

-        private const string message = "The user does not exist.";

-

-        public UserNotExistException(string username)

-            : base(FormatLogMessage(message, Pair("Username", username)))

-        {

-            Username = username;

-        }

-

-        public UserNotExistException(long id)

-            : base(FormatLogMessage(message, Pair("Id", id)))

-        {

-            Id = id;

-        }

-

-        public UserNotExistException(string message, Exception inner) : base(message, inner) { }

-

-        protected UserNotExistException(

-          System.Runtime.Serialization.SerializationInfo info,

-          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

-

-        /// <summary>

-        /// The username that does not exist. May be null then <see cref="Id"/> is not null.

-        /// </summary>

-        public string Username { get; private set; }

-

-        /// <summary>

-        /// The id that does not exist. May be null then <see cref="Username"/> is not null.

-        /// </summary>

-        public long? Id { get; private set; }

-    }

-

-    [Serializable]

-    public class BadPasswordException : Exception

-    {

-        public BadPasswordException(string badPassword)

-            : base(FormatLogMessage("Password is wrong.", Pair("Bad Password", badPassword)))

-        {

-            Password = badPassword;

-        }

-

-        public BadPasswordException(string message, Exception inner) : base(message, inner) { }

-

-        protected BadPasswordException(

-          System.Runtime.Serialization.SerializationInfo info,

-          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

-

-        /// <summary>

-        /// The wrong password.

-        /// </summary>

-        public string Password { get; private set; }

-    }

-

-

-    [Serializable]

-    public class BadTokenVersionException : Exception

-    {

-        public BadTokenVersionException(long tokenVersion, long requiredVersion)

-            : base(FormatLogMessage("Token version is expired.",

-                Pair("Token Version", tokenVersion),

-                Pair("Required Version", requiredVersion)))

-        {

-            TokenVersion = tokenVersion;

-            RequiredVersion = requiredVersion;

-        }

-

-        public BadTokenVersionException(string message, Exception inner) : base(message, inner) { }

-

-        protected BadTokenVersionException(

-          System.Runtime.Serialization.SerializationInfo info,

-          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

-

-        /// <summary>

-        /// The version in the token.

-        /// </summary>

-        public long TokenVersion { get; private set; }

-

-        /// <summary>

-        /// The version required.

-        /// </summary>

-        public long RequiredVersion { get; private set; }

-    }

-

-    /// <summary>

-    /// Thrown when username is of bad format.

-    /// </summary>

-    [Serializable]

-    public class UsernameBadFormatException : Exception

-    {

-        public UsernameBadFormatException(string username, string message) : base(message) { Username = username; }

-        public UsernameBadFormatException(string username, string message, Exception inner) : base(message, inner) { Username = username; }

-        protected UsernameBadFormatException(

-          System.Runtime.Serialization.SerializationInfo info,

-          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

-

-        /// <summary>

-        /// Username of bad format.

-        /// </summary>

-        public string Username { get; private set; }

-    }

-

-

-    /// <summary>

-    /// Thrown when the user already exists.

-    /// </summary>

-    [Serializable]

-    public class UserAlreadyExistException : Exception

-    {

-        public UserAlreadyExistException(string username) : base($"User {username} already exists.") { Username = username; }

-        public UserAlreadyExistException(string username, string message) : base(message) { Username = username; }

-        public UserAlreadyExistException(string message, Exception inner) : base(message, inner) { }

-        protected UserAlreadyExistException(

-          System.Runtime.Serialization.SerializationInfo info,

-          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

-

-        /// <summary>

-        /// The username that already exists.

-        /// </summary>

-        public string Username { get; set; }

+        public string Token { get; set; } = default!;

+        public UserInfo User { get; set; } = default!;

     }

 

     public interface IUserService

@@ -152,6 +28,7 @@ namespace Timeline.Services
         /// <param name="expires">The expired time point. Null then use default. See <see cref="JwtService.GenerateJwtToken(TokenInfo, DateTime?)"/> for what is default.</param>

         /// <returns>An <see cref="CreateTokenResult"/> containing the created token and user info.</returns>

         /// <exception cref="ArgumentNullException">Thrown when <paramref name="username"/> or <paramref name="password"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown when username is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown when the user with given username does not exist.</exception>

         /// <exception cref="BadPasswordException">Thrown when password is wrong.</exception>

         Task<CreateTokenResult> CreateToken(string username, string password, DateTime? expires = null);

@@ -163,9 +40,8 @@ namespace Timeline.Services
         /// <param name="token">The token to verify.</param>

         /// <returns>The user info specified by the token.</returns>

         /// <exception cref="ArgumentNullException">Thrown when <paramref name="token"/> is null.</exception>

-        /// <exception cref="JwtTokenVerifyException">Thrown when the token is of bad format. Thrown by <see cref="JwtService.VerifyJwtToken(string)"/>.</exception>

+        /// <exception cref="JwtVerifyException">Thrown when the token is of bad format. Thrown by <see cref="JwtService.VerifyJwtToken(string)"/>.</exception>

         /// <exception cref="UserNotExistException">Thrown when the user specified by the token does not exist. Usually it has been deleted after the token was issued.</exception>

-        /// <exception cref="BadTokenVersionException">Thrown when the version in the token is expired. User needs to recreate the token.</exception>

         Task<UserInfo> VerifyToken(string token);

 

         /// <summary>

@@ -173,6 +49,8 @@ namespace Timeline.Services
         /// </summary>

         /// <param name="username">Username of the user.</param>

         /// <returns>The info of the user. Null if the user of given username does not exists.</returns>

+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="username"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown when <paramref name="username"/> is of bad format.</exception>

         Task<UserInfo> GetUser(string username);

 

         /// <summary>

@@ -188,10 +66,12 @@ namespace Timeline.Services
         /// <param name="username">Username of user.</param>

         /// <param name="password">Password of user.</param>

         /// <param name="administrator">Whether the user is administrator.</param>

-        /// <returns>Return <see cref="PutResult.Created"/> if a new user is created.

-        /// Return <see cref="PutResult.Modified"/> if a existing user is modified.</returns>

-        /// <exception cref="UsernameBadFormatException">Thrown when <paramref name="username"/> is of bad format.</exception>

+        /// <returns>

+        /// Return <see cref="PutResult.Create"/> if a new user is created.

+        /// Return <see cref="PutResult.Modify"/> if a existing user is modified.

+        /// </returns>

         /// <exception cref="ArgumentNullException">Thrown when <paramref name="username"/> or <paramref name="password"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown when <paramref name="username"/> is of bad format.</exception>

         Task<PutResult> PutUser(string username, string password, bool administrator);

 

         /// <summary>

@@ -203,14 +83,16 @@ namespace Timeline.Services
         /// <param name="password">New password. Null if not modify.</param>

         /// <param name="administrator">Whether the user is administrator. Null if not modify.</param>

         /// <exception cref="ArgumentNullException">Thrown if <paramref name="username"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown when <paramref name="username"/> is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown if the user with given username does not exist.</exception>

-        Task PatchUser(string username, string password, bool? administrator);

+        Task PatchUser(string username, string? password, bool? administrator);

 

         /// <summary>

         /// Delete a user of given username.

         /// </summary>

         /// <param name="username">Username of thet user to delete. Can't be null.</param>

         /// <exception cref="ArgumentNullException">Thrown if <paramref name="username"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown when <paramref name="username"/> is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown if the user with given username does not exist.</exception>

         Task DeleteUser(string username);

 

@@ -221,6 +103,7 @@ namespace Timeline.Services
         /// <param name="oldPassword">The user's old password.</param>

         /// <param name="newPassword">The user's new password.</param>

         /// <exception cref="ArgumentNullException">Thrown if <paramref name="username"/> or <paramref name="oldPassword"/> or <paramref name="newPassword"/> is null.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown when <paramref name="username"/> is of bad format.</exception>

         /// <exception cref="UserNotExistException">Thrown if the user with given username does not exist.</exception>

         /// <exception cref="BadPasswordException">Thrown if the old password is wrong.</exception>

         Task ChangePassword(string username, string oldPassword, string newPassword);

@@ -230,16 +113,16 @@ namespace Timeline.Services
         /// </summary>

         /// <param name="oldUsername">The user's old username.</param>

         /// <param name="newUsername">The new username.</param>

-        /// <exception cref="ArgumentException">Thrown if <paramref name="oldUsername"/> or <paramref name="newUsername"/> is null or empty.</exception>

+        /// <exception cref="ArgumentNullException">Thrown if <paramref name="oldUsername"/> or <paramref name="newUsername"/> is null.</exception>

         /// <exception cref="UserNotExistException">Thrown if the user with old username does not exist.</exception>

-        /// <exception cref="UsernameBadFormatException">Thrown if the new username is not accepted because of bad format.</exception>

-        /// <exception cref="UserAlreadyExistException">Thrown if user with the new username already exists.</exception>

+        /// <exception cref="UsernameBadFormatException">Thrown if the <paramref name="oldUsername"/> or <paramref name="newUsername"/> is of bad format.</exception>

+        /// <exception cref="UsernameConfictException">Thrown if user with the new username already exists.</exception>

         Task ChangeUsername(string oldUsername, string newUsername);

     }

 

     internal class UserCache

     {

-        public string Username { get; set; }

+        public string Username { get; set; } = default!;

         public bool Administrator { get; set; }

         public long Version { get; set; }

 

@@ -272,13 +155,25 @@ namespace Timeline.Services
             _usernameValidator = new UsernameValidator();

         }

 

-        private string GenerateCacheKeyByUserId(long id) => $"user:{id}";

+        private static string GenerateCacheKeyByUserId(long id) => $"user:{id}";

 

         private void RemoveCache(long id)

         {

             var key = GenerateCacheKeyByUserId(id);

             _memoryCache.Remove(key);

-            _logger.LogInformation(FormatLogMessage("A cache entry is removed.", Pair("Key", key)));

+            _logger.LogInformation(Log.Format(Resources.Services.UserService.LogCacheRemove, ("Key", key)));

+        }

+

+        private void CheckUsernameFormat(string username, string? message = null)

+        {

+            var (result, messageGenerator) = _usernameValidator.Validate(username);

+            if (!result)

+            {

+                if (message == null)

+                    throw new UsernameBadFormatException(username, messageGenerator(null));

+                else

+                    throw new UsernameBadFormatException(username, message + messageGenerator(null));

+            }

         }

 

         public async Task<CreateTokenResult> CreateToken(string username, string password, DateTime? expires)

@@ -287,6 +182,7 @@ namespace Timeline.Services
                 throw new ArgumentNullException(nameof(username));

             if (password == null)

                 throw new ArgumentNullException(nameof(password));

+            CheckUsernameFormat(username);

 

             // We need password info, so always check the database.

             var user = await _databaseContext.Users.Where(u => u.Name == username).SingleOrDefaultAsync();

@@ -306,7 +202,7 @@ namespace Timeline.Services
             return new CreateTokenResult

             {

                 Token = token,

-                User = CreateUserInfo(user)

+                User = UserConvert.CreateUserInfo(user)

             };

         }

 

@@ -329,29 +225,33 @@ namespace Timeline.Services
                     throw new UserNotExistException(id);

 

                 // create cache

-                cache = CreateUserCache(user);

+                cache = UserConvert.CreateUserCache(user);

                 _memoryCache.CreateEntry(key).SetValue(cache);

-                _logger.LogInformation(FormatLogMessage("A cache entry is created.", Pair("Key", key)));

+                _logger.LogInformation(Log.Format(Resources.Services.UserService.LogCacheCreate, ("Key", key)));

             }

 

             if (tokenInfo.Version != cache.Version)

-                throw new BadTokenVersionException(tokenInfo.Version, cache.Version);

+                throw new JwtVerifyException(new JwtBadVersionException(tokenInfo.Version, cache.Version), JwtVerifyException.ErrorCodes.OldVersion);

 

             return cache.ToUserInfo();

         }

 

         public async Task<UserInfo> GetUser(string username)

         {

+            if (username == null)

+                throw new ArgumentNullException(nameof(username));

+            CheckUsernameFormat(username);

+

             return await _databaseContext.Users

                 .Where(user => user.Name == username)

-                .Select(user => CreateUserInfo(user))

+                .Select(user => UserConvert.CreateUserInfo(user))

                 .SingleOrDefaultAsync();

         }

 

         public async Task<UserInfo[]> ListUsers()

         {

             return await _databaseContext.Users

-                .Select(user => CreateUserInfo(user))

+                .Select(user => UserConvert.CreateUserInfo(user))

                 .ToArrayAsync();

         }

 

@@ -361,11 +261,7 @@ namespace Timeline.Services
                 throw new ArgumentNullException(nameof(username));

             if (password == null)

                 throw new ArgumentNullException(nameof(password));

-

-            if (!_usernameValidator.Validate(username, out var message))

-            {

-                throw new UsernameBadFormatException(username, message);

-            }

+            CheckUsernameFormat(username);

 

             var user = await _databaseContext.Users.Where(u => u.Name == username).SingleOrDefaultAsync();

 

@@ -375,31 +271,34 @@ namespace Timeline.Services
                 {

                     Name = username,

                     EncryptedPassword = _passwordService.HashPassword(password),

-                    RoleString = IsAdminToRoleString(administrator),

-                    Avatar = UserAvatar.Create(DateTime.Now)

+                    RoleString = UserRoleConvert.ToString(administrator),

+                    Avatar = null

                 };

                 await _databaseContext.AddAsync(newUser);

                 await _databaseContext.SaveChangesAsync();

-                _logger.LogInformation(FormatLogMessage("A new user entry is added to the database.", Pair("Id", newUser.Id)));

-                return PutResult.Created;

+                _logger.LogInformation(Log.Format(Resources.Services.UserService.LogDatabaseCreate,

+                    ("Id", newUser.Id), ("Username", username), ("Administrator", administrator)));

+                return PutResult.Create;

             }

 

             user.EncryptedPassword = _passwordService.HashPassword(password);

-            user.RoleString = IsAdminToRoleString(administrator);

+            user.RoleString = UserRoleConvert.ToString(administrator);

             user.Version += 1;

             await _databaseContext.SaveChangesAsync();

-            _logger.LogInformation(FormatLogMessage("A user entry is updated to the database.", Pair("Id", user.Id)));

+            _logger.LogInformation(Log.Format(Resources.Services.UserService.LogDatabaseUpdate,

+                ("Id", user.Id), ("Username", username), ("Administrator", administrator)));

 

             //clear cache

             RemoveCache(user.Id);

 

-            return PutResult.Modified;

+            return PutResult.Modify;

         }

 

-        public async Task PatchUser(string username, string password, bool? administrator)

+        public async Task PatchUser(string username, string? password, bool? administrator)

         {

             if (username == null)

                 throw new ArgumentNullException(nameof(username));

+            CheckUsernameFormat(username);

 

             var user = await _databaseContext.Users.Where(u => u.Name == username).SingleOrDefaultAsync();

             if (user == null)

@@ -412,12 +311,12 @@ namespace Timeline.Services
 

             if (administrator != null)

             {

-                user.RoleString = IsAdminToRoleString(administrator.Value);

+                user.RoleString = UserRoleConvert.ToString(administrator.Value);

             }

 

             user.Version += 1;

             await _databaseContext.SaveChangesAsync();

-            _logger.LogInformation(FormatLogMessage("A user entry is updated to the database.", Pair("Id", user.Id)));

+            _logger.LogInformation(Resources.Services.UserService.LogDatabaseUpdate, ("Id", user.Id));

 

             //clear cache

             RemoveCache(user.Id);

@@ -427,6 +326,7 @@ namespace Timeline.Services
         {

             if (username == null)

                 throw new ArgumentNullException(nameof(username));

+            CheckUsernameFormat(username);

 

             var user = await _databaseContext.Users.Where(u => u.Name == username).SingleOrDefaultAsync();

             if (user == null)

@@ -434,7 +334,8 @@ namespace Timeline.Services
 

             _databaseContext.Users.Remove(user);

             await _databaseContext.SaveChangesAsync();

-            _logger.LogInformation(FormatLogMessage("A user entry is removed from the database.", Pair("Id", user.Id)));

+            _logger.LogInformation(Log.Format(Resources.Services.UserService.LogDatabaseRemove,

+                ("Id", user.Id)));

 

             //clear cache

             RemoveCache(user.Id);

@@ -448,6 +349,7 @@ namespace Timeline.Services
                 throw new ArgumentNullException(nameof(oldPassword));

             if (newPassword == null)

                 throw new ArgumentNullException(nameof(newPassword));

+            CheckUsernameFormat(username);

 

             var user = await _databaseContext.Users.Where(u => u.Name == username).SingleOrDefaultAsync();

             if (user == null)

@@ -460,19 +362,20 @@ namespace Timeline.Services
             user.EncryptedPassword = _passwordService.HashPassword(newPassword);

             user.Version += 1;

             await _databaseContext.SaveChangesAsync();

+            _logger.LogInformation(Log.Format(Resources.Services.UserService.LogDatabaseUpdate,

+                ("Id", user.Id), ("Operation", "Change password")));

             //clear cache

             RemoveCache(user.Id);

         }

 

         public async Task ChangeUsername(string oldUsername, string newUsername)

         {

-            if (string.IsNullOrEmpty(oldUsername))

-                throw new ArgumentException("Old username is null or empty", nameof(oldUsername));

-            if (string.IsNullOrEmpty(newUsername))

-                throw new ArgumentException("New username is null or empty", nameof(newUsername));

-

-            if (!_usernameValidator.Validate(newUsername, out var message))

-                throw new UsernameBadFormatException(newUsername, $"New username is of bad format. {message}");

+            if (oldUsername == null)

+                throw new ArgumentNullException(nameof(oldUsername));

+            if (newUsername == null)

+                throw new ArgumentNullException(nameof(newUsername));

+            CheckUsernameFormat(oldUsername, Resources.Services.UserService.ExceptionOldUsernameBadFormat);

+            CheckUsernameFormat(newUsername, Resources.Services.UserService.ExceptionNewUsernameBadFormat);

 

             var user = await _databaseContext.Users.Where(u => u.Name == oldUsername).SingleOrDefaultAsync();

             if (user == null)

@@ -480,13 +383,13 @@ namespace Timeline.Services
 

             var conflictUser = await _databaseContext.Users.Where(u => u.Name == newUsername).SingleOrDefaultAsync();

             if (conflictUser != null)

-                throw new UserAlreadyExistException(newUsername);

+                throw new UsernameConfictException(newUsername);

 

             user.Name = newUsername;

             user.Version += 1;

             await _databaseContext.SaveChangesAsync();

-            _logger.LogInformation(FormatLogMessage("A user entry changed name field.",

-                Pair("Id", user.Id), Pair("Old Username", oldUsername), Pair("New Username", newUsername)));

+            _logger.LogInformation(Log.Format(Resources.Services.UserService.LogDatabaseUpdate,

+                ("Id", user.Id), ("Old Username", oldUsername), ("New Username", newUsername)));

             RemoveCache(user.Id);

         }

     }

diff --git a/Timeline/Services/UsernameBadFormatException.cs b/Timeline/Services/UsernameBadFormatException.cs
new file mode 100644
index 00000000..04354d22
--- /dev/null
+++ b/Timeline/Services/UsernameBadFormatException.cs
@@ -0,0 +1,27 @@
+using System;

+

+namespace Timeline.Services

+{

+    /// <summary>

+    /// Thrown when username is of bad format.

+    /// </summary>

+    [Serializable]

+    public class UsernameBadFormatException : Exception

+    {

+        public UsernameBadFormatException() : base(Resources.Services.Exception.UsernameBadFormatException) { }

+        public UsernameBadFormatException(string message) : base(message) { }

+        public UsernameBadFormatException(string message, Exception inner) : base(message, inner) { }

+

+        public UsernameBadFormatException(string username, string message) : base(message) { Username = username; }

+        public UsernameBadFormatException(string username, string message, Exception inner) : base(message, inner) { Username = username; }

+

+        protected UsernameBadFormatException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+

+        /// <summary>

+        /// Username of bad format.

+        /// </summary>

+        public string? Username { get; private set; }

+    }

+}

diff --git a/Timeline/Services/UsernameConfictException.cs b/Timeline/Services/UsernameConfictException.cs
new file mode 100644
index 00000000..fde1eda6
--- /dev/null
+++ b/Timeline/Services/UsernameConfictException.cs
@@ -0,0 +1,25 @@
+using System;

+using Timeline.Helpers;

+

+namespace Timeline.Services

+{

+    /// <summary>

+    /// Thrown when the user already exists.

+    /// </summary>

+    [Serializable]

+    public class UsernameConfictException : Exception

+    {

+        public UsernameConfictException() : base(Resources.Services.Exception.UsernameConfictException) { }

+        public UsernameConfictException(string username) : base(Log.Format(Resources.Services.Exception.UsernameConfictException, ("Username", username))) { Username = username; }

+        public UsernameConfictException(string username, string message) : base(message) { Username = username; }

+        public UsernameConfictException(string message, Exception inner) : base(message, inner) { }

+        protected UsernameConfictException(

+          System.Runtime.Serialization.SerializationInfo info,

+          System.Runtime.Serialization.StreamingContext context) : base(info, context) { }

+

+        /// <summary>

+        /// The username that already exists.

+        /// </summary>

+        public string? Username { get; set; }

+    }

+}

diff --git a/Timeline/Startup.cs b/Timeline/Startup.cs
index 8e8a6393..b44add6f 100644
--- a/Timeline/Startup.cs
+++ b/Timeline/Startup.cs
@@ -2,10 +2,13 @@ using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Cors.Infrastructure;

 using Microsoft.AspNetCore.Hosting;

 using Microsoft.AspNetCore.HttpOverrides;

+using Microsoft.AspNetCore.Localization;

 using Microsoft.EntityFrameworkCore;

 using Microsoft.Extensions.Configuration;

 using Microsoft.Extensions.DependencyInjection;

-using Timeline.Authenticate;

+using System.Collections.Generic;

+using System.Globalization;

+using Timeline.Authentication;

 using Timeline.Configs;

 using Timeline.Entities;

 using Timeline.Helpers;

@@ -13,6 +16,7 @@ using Timeline.Services;
 

 namespace Timeline

 {

+    [System.Diagnostics.CodeAnalysis.SuppressMessage("Performance", "CA1822:Mark members as static")]

     public class Startup

     {

         public Startup(IConfiguration configuration, IWebHostEnvironment environment)

@@ -27,11 +31,12 @@ namespace Timeline
         // This method gets called by the runtime. Use this method to add services to the container.

         public void ConfigureServices(IServiceCollection services)

         {

-            services.AddMvc()

+            services.AddControllers()

                 .ConfigureApiBehaviorOptions(options =>

                 {

                     options.InvalidModelStateResponseFactory = InvalidModelResponseFactory.Factory;

-                });

+                })

+                .AddNewtonsoftJson();

 

             services.Configure<JwtConfig>(Configuration.GetSection(nameof(JwtConfig)));

             var jwtConfig = Configuration.GetSection(nameof(JwtConfig)).Get<JwtConfig>();

@@ -48,13 +53,17 @@ namespace Timeline
                 );

             });

 

+            services.AddLocalization(options =>

+            {

+                options.ResourcesPath = "Resources";

+            });

+

             services.AddScoped<IUserService, UserService>();

             services.AddScoped<IJwtService, JwtService>();

             services.AddTransient<IPasswordService, PasswordService>();

             services.AddTransient<IClock, Clock>();

 

             services.AddUserAvatarService();

-            services.AddUserDetailService();

 

             var databaseConfig = Configuration.GetSection(nameof(DatabaseConfig)).Get<DatabaseConfig>();

 

@@ -63,11 +72,10 @@ namespace Timeline
                 options.UseMySql(databaseConfig.ConnectionString);

             });

 

-            services.AddHttpClient();

-

             services.AddMemoryCache();

         }

 

+

         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.

         public void Configure(IApplicationBuilder app)

         {

@@ -78,6 +86,19 @@ namespace Timeline
 

             app.UseRouting();

 

+            var supportedCultures = new List<CultureInfo>

+            {

+                new CultureInfo("en"),

+                new CultureInfo("zh")

+            };

+

+            app.UseRequestLocalization(new RequestLocalizationOptions

+            {

+                DefaultRequestCulture = new RequestCulture("en"),

+                SupportedCultures = supportedCultures,

+                SupportedUICultures = supportedCultures

+            });

+

             app.UseCors();

 

             app.UseAuthentication();

diff --git a/Timeline/Timeline.csproj b/Timeline/Timeline.csproj
index f01b8e31..519a802d 100644
--- a/Timeline/Timeline.csproj
+++ b/Timeline/Timeline.csproj
@@ -4,6 +4,9 @@
         <IsPackable>false</IsPackable>

         <UserSecretsId>1f6fb74d-4277-4bc0-aeea-b1fc5ffb0b43</UserSecretsId>

         <Authors>crupest</Authors>

+

+        <LangVersion>8.0</LangVersion>

+        <Nullable>enable</Nullable>

     </PropertyGroup>

 

     <ItemGroup>

@@ -13,9 +16,127 @@
     </ItemGroup>

 

     <ItemGroup>

+        <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.0.0" />

+        <PackageReference Include="Microsoft.CodeAnalysis.FxCopAnalyzers" Version="2.9.6">

+            <PrivateAssets>all</PrivateAssets>

+            <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

+        </PackageReference>

+        <PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.0.0" />

+        <PackageReference Include="Microsoft.EntityFrameworkCore.Analyzers" Version="3.0.0" />

+        <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.0.0">

+          <PrivateAssets>all</PrivateAssets>

+          <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

+        </PackageReference>

         <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="3.0.0-rc1.final" />

         <PackageReference Include="Pomelo.EntityFrameworkCore.MySql.Design" Version="1.1.2" />

         <PackageReference Include="SixLabors.ImageSharp" Version="1.0.0-dev002868" />

-        <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="5.5.0" />

+        <PackageReference Include="System.IdentityModel.Tokens.Jwt" Version="5.6.0" />

+    </ItemGroup>

+

+    <ItemGroup>

+      <Compile Update="Resources\Authentication\AuthHandler.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>AuthHandler.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Common.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>Common.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Controllers\TokenController.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>TokenController.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Controllers\UserAvatarController.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>UserAvatarController.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Controllers\UserController.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>UserController.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Models\Validation\UsernameValidator.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>UsernameValidator.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Models\Validation\Validator.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>Validator.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Services\Exception.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>Exception.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Services\UserAvatarService.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>UserAvatarService.resx</DependentUpon>

+      </Compile>

+      <Compile Update="Resources\Services\UserService.Designer.cs">

+        <DesignTime>True</DesignTime>

+        <AutoGen>True</AutoGen>

+        <DependentUpon>UserService.resx</DependentUpon>

+      </Compile>

+    </ItemGroup>

+

+    <ItemGroup>

+      <EmbeddedResource Update="Resources\Authentication\AuthHandler.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>AuthHandler.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Common.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>Common.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Controllers\TokenController.resx">

+        <SubType>Designer</SubType>

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>TokenController.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Controllers\TokenController.zh.resx">

+        <SubType>Designer</SubType>

+        <Generator></Generator>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Controllers\TokenController.en.resx">

+        <Generator></Generator>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Controllers\UserAvatarController.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>UserAvatarController.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Controllers\UserController.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>UserController.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Models\Validation\UsernameValidator.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>UsernameValidator.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Models\Validation\Validator.en.resx">

+        <Generator></Generator>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Models\Validation\Validator.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>Validator.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Services\Exception.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>Exception.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Services\UserAvatarService.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>UserAvatarService.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

+      <EmbeddedResource Update="Resources\Services\UserService.resx">

+        <Generator>ResXFileCodeGenerator</Generator>

+        <LastGenOutput>UserService.Designer.cs</LastGenOutput>

+      </EmbeddedResource>

     </ItemGroup>

 </Project>